95 MTX stall... O2 codes

[shorty]

Hi all,
My SHO stalled on me today, I was going about 55, had been driving trouble free for 1.5 hours and she coasted to a stop. I waited about five minutes, wiggled some connections and she started. I got about 100 yards and she stalled again. I did get her to run for about 3 minutes but she died again. I pulled out some paper work and let everything set for about 1.5 hours. After that it started and got me home; about another hours worth of driving. I just pulled the codes, they are:

KOEO:
172: Oxygen sensor not switching - system is or was lean - Single, Right orr Rear HO2S - Fuel control

176: Oxygen sensor not switching - system is or was lean Left or Front HO22SSS - Fuel control

542: Fuel pump open, bad ground or always on - - Power / Fuel Pump Circuits

KOER:
136: Oxygen sensor not switching/system lean Left or Front HO2S - Fuel control

159: MAF sensor is/was out of range - MAF

411: Idle speed system not controlling idle properly (generally idle too high) - ISC

Cylinder Balance was fine.

I'm seeing a lot of O2 stuff here which maybe should clue me in, but as with my CPK codes a couple months ago I would appreciate the input of experience.

Thanks in advance,
Rob

 

[sho'd]

almost sounds like the water pump could be leaking out the vent hole and onto the crank position sensor, just a thought, some of the guru's will point you in the right direction i am sure, good luck.

 

[shorty]

To clarify: The CPK code occured ~3500 miles ago, I replaced the crank sensor and water pump and timing belt. I wouldn't guess that's the problem. I only brought it up as an example of my gratitude for previous help I'd gotten here.
Thanks,
Rob

 

[Storm-Chaser]

My first impression is the fuel pump or fuel pump relay. Any time the vehicle stalls or runs out-of-gas (for any reason) it will kick off a series of HEGO faults which indicate a lean mixture (ie. lack of fuel) as fuel starvation occurs, before engine stall.

Focus on the 542 and 159 fault codes, then the 136 code.

You can verify the HEGO fault codes by clearing the codes, running the engine and pulling the codes again before the vehicle stalls.

First clear the codes and pull them again before starting the vehicle to ensure the codes have cleared. Start the vehicle. If it starts normally (ie. like it did before the problem occurred), let the engine run 30-45 seconds and pull the KOEO codes to see if the HEGO codes are present. If they're not, start the vehicle, bring the engine temp. up to the normal range. Pull the KOEO and KOER codes to see if the MAF sensor code reappears. If the codes are still clear, drive the vehicle a few minutes through the normal operating range (go through all the gears, up to highway speed). Pull the codes again.

If the problem is due to the fuel pump starting to go, it should show-up as the vehicle is accelerated and fuel rail pressure starts to drop due to increased demand compared to what the pump can supply.

When you start replacing parts, replace one item at a time drive the vehicle and pull the codes to see what has cleared. Otherwise you could end-up throwing a lot of money an unrelated problem or causing additional problems in the wiriing harness (ie. inducing a poor connection, loosening a ground, breaking a wire, etc.)



FYI, the OBDS fault code chart I have access to right now, lists the following codes:

KOEO:

172 (R,C) - HEGO (HO2S) sensor fault/lean

176 (C) - HEGO (HO2S) sensor fault/always lean

542 (O,C) - Fuel pump secondary circuit fault​

KOER:

136 (R) - HEGO (HO2S) sensor fault/always lean

159 (O,R) - Mass Air Flow sensor fault, above or below normal

411 (R) - Cannot control RPM during KOER low RPM check
​

Test code:

O = KOEO code
R = KOER code
C = CM code
​

 

[Storm-Chaser]

Oh, how much gas was in the tank at the time?

Have you had any issues with random difficulty starting, hesitation accelerating, or bogging?

How many miles?

Has the fuel pump or filter been changed?

Have you checked the fuel pressure at the fuel rail?

 

[shorty]

Thanks for the input; my answers to your questions:

Oh, how much gas was in the tank at the time?

3/4 tank (I'd filled up before driving ~ 1.5 hours earlier)

Have you had any issues with random difficulty starting, hesitation accelerating, or bogging?

Not random, I often have to turn the ignition key twice to start. The first time it cranks fine, but doesn't catch. Second time is usually the charm. No hesitation or bogging noticed.

How many miles?

170k

Has the fuel pump or filter been changed?

I changed the fuel filter about 3500 miles ago when I was stalling due to a bad crank sensor (before I figured out how to pull codes and actually analyze the car)

Have you checked the fuel pressure at the fuel rail?

I have not checked fuel pressure.

Interesting that you mention fuel pump. When I had the CPK code a few months ago I also had a fuel pump code. It was suggested that the fuel pump code was a "companion" code that occured due to the intermittant CPK failure. Which is still possible. From your previous post I have the impression that the fuel pump code will come up for low pressure (not just abscence of pressure). I will follow the procedure you outlined and hopefully be able to figure out if the fuel pump is on its way out.

I searched other threads with MAF and O2 codes; the reported problems seemd to be rough idle and poor gas milage, not coasting to a stop. From that perspective the fuel pump problem triping the O2 codes makes more sense.

Fortunatley I have alternate transportation so I can do that as I have time.

Unfortunately I work about 3 hours from my workshop (where the car now sits) and I won't get back to it for 2 weeks.

I appreciate your input and will keep you posted on my progress. In the meantime I'll be running my 1973 F100 and 1971 Moto Guzzi.

Rob

 

[Markus]

According to the Ford manual you should address the codes in the order the EEC gives them to you. Regarding the 542: bad O2 sensors always trigger this code (and 543) when triggering 172, 176, and others. It's just the nature of the beast. See if you can get your hands on the real Ford service manual. It will give you the proicedures to step through for each code. If you can't get the manual I'd start with replacing the O2 sensors and clearing the codes and move on from there.

 

[Storm-Chaser]

I disagree.

These codes are triggered by more than just a bad oxygen sensor. The 172/176 codes imply that both sensors (left and right) have failed, and both are defaulting to an oxygen-rich (lean) condition. Simply running out of gas will trigger the mentioned oxygen sensor codes. I have also seen both a weak alternator as well as a bad voltage regulator cause these same codes to kick-out, in addition to TPS (Throttle Position Sensor) and MAF codes. I think to start out by simply throwing a $100 (or more, for oxygen sensors) at the problem without checking for reoccurence with the engine running (before it cuts-out or stalls), is premature.

Additionally, all the KOEO codes either are or may be Continuous Memory codes (stored) and may simply be the result of a prior problem if the codes were not previously cleared.

If it is the oxygen sensors, the codes will reappear before the vehicles stalls due to fuel starvation.


Here's some additional food-for-thought....

The Fuel Pump Relay is contained within the PCM relay (Powertrain Control Module Relay). The powertrain control module relay is controlled by the Powertrain Control Module. The PCM is located behind the glove box and connected to the primary wring harness via a 60-pin connector on the firewall. There are a number of threads of other SHO owners having a host of unresolvable problems that are ultimately traced back to corrosion at this connector.

Note some of the PCM circuit functions below:

Power Control Module Connector pin-out

pin 09 - MAF return
pin 12 - Fuel Injector no. 3
pin 13 - Fuel Injector no. 4
pin 14 - Fuel Injector no. 5
pin 15 - Fuel Injector no. 6
pin 16 - Ignition Ground
pin 19 - Fuel Pump Monitor
pin 21 - Idle Air Control
pin 22 - Low Speed Fuel Pump Relay
pin 24 - CKP Sensor
pin 29 - HO2S Sensor no. 1
pin 32 - Idle Air Control
pin 36 - Spark Output
pin 41 - PCM to High-Speed Fuel Pump
pin 43 - HO2S Sensor no. 2
pin 47 - Throttle Position Sensor
pin 49 - HO2S Ground
pin 50 - MAF Sensor
pin 58 - Fuel Injector no. 1
pin 59 - Fuel Injector no. 2
​

So if it isn't the MAF and/or fuel pump, I would next suspect the PCM based on the commonality of the problems you've had, codes your still getting, and the components affected. Have you check for corrosion of the terminals on the PCM connectors? You mentioned "wiggling" the wires and getting it to run for a short period of time.

The Taurus Service Manual does not contain information for diagnosing ODBS codes, the PCED manual does (Powertrain Control/ Emissions Diagnostic). This is a very bulky manual that very few shops are likely to have, and that many dealerships aren't going to give you access to, unless you know someone at the dealership or in the service department.

 

[Mr Anonymous]

Fuel pump codes after a stalling situation are often misleading as the PCM will set the code because the fuel pump continues to run for a couple of seconds after the PCM has stopped receiving CKP data because of the logic ladder in the PCM. IOW, the PCM sees the fuel pump running (which it is still commanding) after it knows the engine isn't running, but because of the way the firmware is written it stores the fuel pump code as a fault even though the fuel pump and circuit is probably perfectly fine.

The MAF code tells me pretty much all that's needed in your situation. My first step would be to try cleaning the MAF filaments with a non-residue electrical contact cleaner. Because of the nature of the symptoms you've described however, I'd suspect that simply cleaning the MAF filaments may not be enough and the MAF sensor itself may be failing, so you may need to try a known good MAF. The O2 codes are simply an extension of the MAF problem as the MAF is likely telling the PCM that it's seeing a lot less air than is actually flowing into motor, thus commanding less fuel than needed and causing the O2's to stop switching and fire lean codes.

 

[Mr Anonymous]

Any time the vehicle stalls or runs out-of-gas (for any reason) it will kick off a series of HEGO faults which indicate a lean mixture (ie. lack of fuel) as fuel starvation occurs, before engine stall.

Ahhhhhh, no.

O2 codes are the result of trending, or sustained readings over a length of time that don't respond properly to changes in air or fuel. The length of time necessary to fire those codes are not going to be long enough during a fuel exhaustion event. The PCM sees rich and lean spikes very frequently, for which it does not set codes, and esentially a fuel exhaustion situation is going to register as a brief series of spikes and not a sustained condition prior to the engine stalling. There are also situations such as coasting fuel shutoff where the motor is basically just an air pump so the O2's are reading solid lean during these events and don't fire codes, but that's a little outside the scope of what's being discussed here.

In the event of fuel starvation due to a fuel delivery issue (whether it be fuel pump, filter, pressure, or injector-related), you're also likely to see adaptive limit codes such as 171/175 because over time the PCM will try pulling or adding as much fuel as it can within the limits of the applicable tables in the calibration.

The Fuel Pump Relay is contained within the PCM (Powertrain Control Module).

No again.

The fuel pump relay is contained within the CCRM mounted to the radiator support underneath the plastic radiator sight shield.

What the PCM does via pin 22 is pull the negative side of the fuel pump relay coil in the CCRM to ground, firing the fuel pump relay. Now technically, pin 22 of the PCM is indeed pulled to ground by a solid state relay, but the fuel pump actually gets its power via the electromechanical relay within the CCRM.

 

[Storm-Chaser]

First off, let me start out by saying thank you for entering a discussion, versus the lack of civil discourse (sp?) that has seems to have become the norm here lately.

Ahhhhhh, no.

O2 codes are the result of trending, or sustained readings over a length of time that don't respond properly to changes in air or fuel. The length of time necessary to fire those codes are not going to be long enough during a fuel exhaustion event. The PCM sees rich and lean spikes very frequently, for which it does not set codes, and esentially a fuel exhaustion situation is going to register as a brief series of spikes and not a sustained condition prior to the engine stalling. There are also situations such as coasting fuel shutoff where the motor is basically just an air pump so the O2's are reading solid lean during these events and don't fire codes, but that's a little outside the scope of what's being discussed here.

In the event of fuel starvation due to a fuel delivery issue (whether it be fuel pump, filter, pressure, or injector-related), you're also likely to see adaptive limit codes such as 171/175 because over time the PCM will try pulling or adding as much fuel as it can within the limits of the applicable tables in the calibration.

That's in theory and design, but I've had the above situation occur real-world (lean-event codes during low fuel pressure/starvation). So, just how long of a "trend" does it take? Just how long of a lean-event/how many event cycles does this take to trigger one or more lean-event codes? Are they base on 'value ranges' (ie. between xx and yy occurences) or absolute values (eg. after three occurrences above *** ppm, code ZZZ will be generated and stored within the EEC) (or, eg. if EGO remains above *** ppm for more than y seconds, code ZZZ will be generated and stored within the EEC)?

And are these criteria the same for all years, or were they changed from one year to the next as the OBDS I/II evolved? Was there a significant change between the OBDS I nd II (ie. GenI/II and Gen III)? Btw, I would really like to get a copy or literature reference if it's available.

I have had this very issue occur in an instance where the fuel pump began to fail. Basically, when the fuel got down to the last few gallons, at some point the vehicle would begin to cut-out and stall at higher rpm. If I backed out of the throttle to below 2000 rpm, the vehicle would continue to run/drive for the next 5-8 miles before eventually dropping to where it could only idle. If I attempted to accelerate with more than 1/4 throttle or pull a relatively steep incline, it would begin to bog, cut-out, and act like it was going to stall until I got out of the throttle. In every case where I pulled the codes, it generated 172/176/and one or more fuel pump circuit faults/failures. Once the pump was changed, all symptoms and all codes did not reappear.

I was surprised when I pulled the pump and found that the pickup strainer was not clogged or even partially blocked. So I suspect that the problem was a factory original fuel pump that was unable to maintain output once the fuel dropped to a low-level. I believe there was a TSB on this problem some years back, that once the pump was exposed by low fuel level, it reduced/eliminated the fuel's ability to help cool and dissipate heat from the fuel pump (if I remember correctly).

If you re-read the OP, shorty had four starvation events in a 2-hour period. This does not include prior events that may have occurred that went unnoticed.

In the two instances where the alternator and voltage regulator ended-up being the problem, low/irregular voltage output resulted in 172/176/ and MAF codes (alternator), and 172/176/MAF/TPS codes (voltage regulator). Again, in both cases the codes did not reappear once the alternators were replaced (later case the voltage regular was bad, which is built into the alternator).

No again.

The fuel pump relay is contained within the CCRM mounted to the radiator support underneath the plastic radiator sight shield.

What the PCM does via pin 22 is pull the negative side of the fuel pump relay coil in the CCRM to ground, firing the fuel pump relay. Now technically, pin 22 of the PCM is indeed pulled to ground by a solid state relay, but the fuel pump actually gets its power via the electromechanical relay within the CCRM.

The fuel pump relay is contained within the powertrain control module relay (PCM relay), which I've both seen referred to as being part of the CCRM, as well as used synonomously in place of constant control relay module (CCRM). I probably re-read that a half-dozen times (editing) before posting, and reading 'relay' into it every time. Shit happens when you've been up 16 hours and try to compose something comprehendable. Thanks for catching the typo - I'll correct it for those that may not read the entire thread.

The powertrain control module relay (PCM relay) includes a number of relays, to include the air conditioning relay control, cooling fan motor relay, fuel pump realy, low fan control, and high fan control.


From the Ford Service Manual

Constant Control Relay Module (CCRM)

The constant control relay module (CCRM) activates
the cooling fan motor when the coolant reaches a
specificied temperature or when the engine reaches a
specified temperature. On vehicles equipped with air
conditioning, the cooling fan motor is activated
whenever the A/C clutch is engaged.

NOTE: Cooling fan motor will not cycle with the A/C
clutch on.

An exception to this is when vehicle speed is over 72
km/h (45 mph) and coolant temperature is below
104 C (220 F). The fan will then automaticallly shut
off.

The coolling fan is controlled during vehicle operation
by the powertrain control module relay (PCM
relay)(12B577) and powertrain control module which
energize the cooling fan under the following conditions:

• Cooling fan is turned on for the 3.0L SHO and on at
  low speed for 3.0L, 3.2L SHO, and 3.8L if:
  
  
  • Engine temperature is higher than normal. (Fan
    starts running at 102 C (215 F) and stops
    running at 99 C (210 F).
    
  • A/C is on and vehicle speed does not provide
    enough natural airflow. (Fan starts running at
    speeds at or below 69 km/h (43 mph) and stops
    running at 77 km/h (48 mph)).

From the Service Manual:

The fuel system has a fuel pump relay controlled by
the powertrain control module (PCM)(12A650), which
provides power to the fuel pump under various
operating conditions.

• When the ignition switch (11572) is in the off
  position:
  
  [*]The contacts of the powertrain control module
  (PCM) and fuel pump relays are open. The fuel
  pump and powertrain control module (PCM)
  relays are contained in the powertrain control
  module relay (PCM relay)(12B577), which is
  service as a separate unit.​
• When the ignition switch is first turned to the on
  position:
  
  [*]The powertrain control module (PCM) power
  relay is energized, closing its contacts.
  [*]Power is provided to both the fuel pump relay and
  to a timing device in the powertrain control module.
  [*]The fuel pump runs through the contacts of the
  fuel pump relay.
  ​
  If the ignition switch is not turned to the START
  position:
  
  [*]The timing device in the powertrain control
  module will open the ground Circuit 57 (after
  approximately one second). Opening the ground
  circuit de-energizes the fuel pump relay, opening
  its contacts, which in-turn de-energizes the fuel
  pump. This circuitry provides for
  pre-pressurization of the fuel system.​
• When the ignition switch is turned to the START
  position:
  
  [*]The powertrain control module operates the fuel
  pump relay to provide fuel for starting the engine
  whlie cranking.
  ​
• After the engine starts and the ignition switch is returned to the ON position:
  
  [*]Power to the fuel pump is again supplied through
  the fuel pump relay.
  [*]The powertrain control module senses engine
  speed and shuts off the fuel pump by opening the
  ground circuit to the fuel pump relay when the
  engine stops or is below 120 rpm.
  ​

​

 

[Mr Anonymous]

Just how long of a lean-event/how many event cycles does this take to trigger one or more lean-event codes? Are they base on 'value ranges' (ie. between xx and yy occurences) or absolute values (eg. after three occurrences above *** ppm, code ZZZ will be generated and stored within the EEC) (or, eg. if EGO remains above *** ppm for more than y seconds, code ZZZ will be generated and stored within the EEC)?

IIRC, it's a function of CKP events counted over a minimum number of PCM clock tics. I don't have the exact numbers handy as I'm in Florida right now, but it's not really useful information for diagnosing 99.99% of the issues people see with these cars other than understanding that simple engine stalling events alone won't usually cause lean codes to be stored.

I have had this very issue occur in an instance where the fuel pump began to fail. Basically, when the fuel got down to the last few gallons, at some point the vehicle would begin to cut-out and stall at higher rpm. If I backed out of the throttle to below 2000 rpm, the vehicle would continue to run/drive for the next 5-8 miles before eventually dropping to where it could only idle. If I attempted to accelerate with more than 1/4 throttle or pull a relatively steep incline, it would begin to bog, cut-out, and act like it was going to stall until I got out of the throttle. In every case where I pulled the codes, it generated 172/176/and one or more fuel pump circuit faults/failures. Once the pump was changed, all symptoms and all codes did not reappear.

By your own description, you were experiencing fuel starvation over an extended period which as I said could result in lean codes being stored because of the length of the lean condition. In this case this person is seeing dead stalls which suggests looking in some other places first.

The fuel pump relay is contained within the powertrain control module relay (PCM relay), which I've both seen referred to as being part of the CCRM, as well as used synonomously in place of constant control relay module (CCRM). I probably re-read that a half-dozen times (editing) before posting, and reading 'relay' into it every time. Shit happens when you've been up 16 hours and try to compose something comprehendable. Thanks for catching the typo - I'll correct it for those that may not read the entire thread.

The thing with quoting from the manual is to remember that the majority of the manuals were written in 1988 or earlier, and only very minor revisions were made through the production cycle. The don't always fully take into account the SAE nomenclature standardizations and such, and they were written for the average Ford technician who isn't always the brightest bulb. It's not unusual to see the service manual and the EVTM refer to the same component in a completely different manner.

It's also important to remember the audience. On this forum, most people are going to understand what is being discussed when the term CCRM (or in the case of Gen I cars, IRCM) is used. Referring to an obscure term used in a manual for an item that people can readily identify as something else just tends to cause confusion.

Diagnosing problems with these cars is generally a very straightforward and simple process, and often the service manual procedures for diganosing certain DTCs or other issues can be overly involved and roundabout.

The bottom line here is that while this person may indeed have a fuel delivery problem, it's not the first logical place to look based on the totality of symptoms and codes. Absent the MAF code I may approach it a little differently, but again a 542 code alone is usually not a "real" code unless it's accompanied by other fuel pump codes.

 

[Markus]

I disagree.

These codes are triggered by more than just a bad oxygen sensor. The 172/176 codes imply that both sensors (left and right) have failed, and both are defaulting to an oxygen-rich (lean) condition. Simply running out of gas will trigger the mentioned oxygen sensor codes. I have also seen both a weak alternator as well as a bad voltage regulator cause these same codes to kick-out, in addition to TPS (Throttle Position Sensor) and MAF codes. I think to start out by simply throwing a $100 (or more, for oxygen sensors) at the problem without checking for reoccurence with the engine running (before it cuts-out or stalls), is premature.


The Taurus Service Manual does not contain information for diagnosing ODBS codes, the PCED manual does (Powertrain Control/ Emissions Diagnostic). This is a very bulky manual that very few shops are likely to have, and that many dealerships aren't going to give you access to, unless you know someone at the dealership or in the service department.

I never said the 542/543 codes could be triggerered ONLY by O2 sensors. It is possible to get codes for both O2 sensors when in fact they are both good. A intake vacuum leak can cause this.

I used the term "service manual" as a generic term for all the factory manuals. I know how bulky they are as I own a full set of them. Purchased through my local Ford dealer. You can also get an electronic version of the manual with, IIRC, links to it on this very forum to them for free Also, for a small annual fee (around $25) you can get access to the info through Alldata. So, if you're inferring that the info in the PCED is hard to come by, you're wrong.

You're right about the weak alternators. With insufficient voltage supplied by the alternator I've seen warning lights for ABS andair bags light up.


Edit: referring to your first post in this thread - I've run out of gas a few times and I've never seen O2 codes set as a result of this.

 

[Storm-Chaser]

....

The thing with quoting from the manual is to remember that the majority of the manuals were written in 1988 or earlier, and only very minor revisions were made through the production cycle. The don't always fully take into account the SAE nomenclature standardizations and such, and they were written for the average Ford technician who isn't always the brightest bulb. It's not unusual to see the service manual and the EVTM refer to the same component in a completely different manner.

It's also important to remember the audience. On this forum, most people are going to understand what is being discussed when the term CCRM (or in the case of Gen I cars, IRCM) is used. Referring to an obscure term used in a manual for an item that people can readily identify as something else just tends to cause confusion.

Call me "old-school" but that's exactly why I use the terms as defined in the Service Manual, as well as quote descriptions and procedures from the various Ford manuals - it provides a means of standardization I can use with "[not] the brightest bulb" (whether that be the dealership or private shop), parts personnel, and others that use the manuals - including parts stores which use online versions of the Helms/Ford Manual (Online Vehicle Repair Guides). That's why I'll also often include both the abbreviation and component name, or the old and new abbreviations, such as "HEGO (HO2S)" as in my first post.

I've not [yet] owned a Gen I, and even though I do have both Gen I Service Manuals and EVTMs, most of those have only been cracked open once or twice to cross reference against the Gen II manuals when researching an obsolete part or tracing an electrical issue. And it was my impression that the later Gen II manuals did use the SAE terminology, as well as list the old abbreviations, acronyms, and terms in the appendix.

Diagnosing problems with these cars is generally a very straightforward and simple process, and often the service manual procedures for diganosing certain DTCs or other issues can be overly involved and roundabout.

While I will agree with that generalization, I was also considering the prior CKP issue that was repaired and that the OP did not indicate [and still has not] whether the codes have ever been cleared after the prior repair. Of the KOEO codes, the 176 code was a CM code, the 542 a CM or KOEO code, and the 172 a CM or KOER code. If all three were residual CM codes, that leaves only the three KOER codes. And in the absence of knowing whether/when the codes were cleared, I posted my first reply so the OP could clear the codes and progressively step through the OBD tests to see what cleared and what re-appeared. His investment would be ~30 minutes time and less than a gallon of gas at most, versus $100 or more simply throwing parts at the problem.

I think you'll agree that the oxygen sensors are not likely to cause the stall and failure to restart. The MAF could, and the fuel pump would, depending on the fault/what has failed. Terminal corrosion could also be a factor, especially given the comments I initially overlooked:

.... I waited about five minutes, wiggled some connections and she started. I got about 100 yards and she stalled again. I did get her to run for about 3 minutes but she died again....

 

[Storm-Chaser]

I never said the 542/543 codes could be triggerered ONLY by O2 sensors. It is possible to get codes for both O2 sensors when in fact they are both good. A intake vacuum leak can cause this.

According to the Ford manual you should address the codes in the order the EEC gives them to you. Regarding the 542: bad O2 sensors always trigger this code (and 543) when triggering 172, 176, and others. It's just the nature of the beast. See if you can get your hands on the real Ford service manual. It will give you the procedures to step through for each code. If you can't get the manual I'd start with replacing the O2 sensors and clearing the codes and move on from there.

You made several very broad generalizations, to include "bad O2 sensors always trigger this code (and 543) when triggering 172, 176, and others....", without qualifying the comment. It would be very easy for someone that's new to the SHO or that does not understand how the OBDS works to mis-interpret this statement as, "it's always bad O2 sensors that trigger this code (and 543) when triggering 172, 176, and others....", implying it's the only fault/failure that triggers the mentioned codes.

I used the term "service manual" as a generic term for all the factory manuals. I know how bulky they are as I own a full set of them. Purchased through my local Ford dealer. You can also get an electronic version of the manual with, IIRC, links to it on this very forum to them for free Also, for a small annual fee (around $25) you can get access to the info through Alldata. So, if you're inferring that the info in the PCED is hard to come by, you're wrong.

You're right about the weak alternators. With insufficient voltage supplied by the alternator I've seen warning lights for ABS andair bags light up.

I've never seen the PCED referred to as "the real Ford service manual....". "Service Manual" has always been the generic reference to the Ford/Helms Service Manual".

I also disagree that the PCED is readily available. The first time I attempt to purchase one, I was told by the dealership that ".... The manual is no longer available, and even if it were, it is a shop-only manual....", implying it was not available for sale (I then usually call my brother, and he tells me who to call to get what I need) So availability is dependent upon the dealership. And do you think dealership is going to: a) tell the owner s/he can buy the PCED and parts, and do the repairs themselves; or, b) write-up a repair estimate? Survey says....

When you consider "who" needs the information, it's usually new/inexperienced owners that don't even know the PCED exists, much less what the abbreviation stands for. Just look at the availability of the PCED versus the Service Manual on eBay.

I use Alldata, and I don't recall seeing links to the PCED online (btw, thanks for the heads-up!). I usually looked-up what I need in a hard copy of the Service Manual, and then go online to print-out the procedure and images (if needed) so I don't trash my manual.

So, if someone is coming here posting requests for answers that have been previously answered and could be found using the search function, what's the likelihood they've going to show the initiative to research something they likely know nothing about, much less pay the subscription fee if they knew it was available? References to the various online manuals are posted in most parts stores, but I have as of yet to hear anyone ask about them, much less buy the actual subscription. Look at the link I posted to the free Autozone guides. They've been available for several years, yet I've never seen it mentioned here, prior to my post.

Is the PCED hard to come by - well, that's relative. It's an issue of people even knowing the online manuals exist (let alone the hardcopy), as well as people's willingness to pay for the online service - even when they do find out it exists. The availability of something you have no idea exists (especially when it's referred to out-of-context), is like someone asking you if you have an Uncle, that no one in your family has ever told you exists.

Edit: referring to your first post in this thread - I've run out of gas a few times and I've never seen O2 codes set as a result of this.

You actually pulled codes simply because you ran out-of-gas?


(sorry, you left yourself wide-open on that one... )

 

[Storm-Chaser]

Rob - please post back what you find out next weekend. Also, were the codes ever cleared after you changed the crank sensor?

IIRC, it's a function of CKP events counted over a minimum number of PCM clock tics. I don't have the exact numbers handy as I'm in Florida right now, but it's not really useful information for diagnosing 99.99% of the issues people see with these cars other than understanding that simple engine stalling events alone won't usually cause lean codes to be stored.

You can PM the reference, unless you think others might be interested in the reference. If anyone else is interested in this, please chime-in.... :wave:

 

[Markus]

You made several very broad generalizations, to include "bad O2 sensors always trigger this code (and 543) when triggering 172, 176, and others....", without qualifying the comment. It would be very easy for someone that's new to the SHO or that does not understand how the OBDS works to mis-interpret this statement as, "it's always bad O2 sensors that trigger this code (and 543) when triggering 172, 176, and others....", implying it's the only fault/failure that triggers the mentioned codes.

Let's not get pedantic. I'd forgotten this this is an internet forum and that every nuance of every statement should be of doctorial quality. If someone wasn't 100% clear about by statement (which did not imply, btw, that 54x codes are generated only when 17x codes are generated) all they need to do is ask. That's how a forum works. Let's not fill up the forums berating somebody for not posting thesis-quality responses.

I've never seen the PCED referred to as "the real Ford service manual....". "Service Manual" has always been the generic reference to the Ford/Helms Service Manual".

You need to broaden your horizons.

I also disagree that the PCED is readily available. The first time I attempt to purchase one, I was told by the dealership that ".... The manual is no longer available, and even if it were, it is a shop-only manual....", implying it was not available for sale (I then usually call my brother, and he tells me who to call to get what I need) So availability is dependent upon the dealership. And do you think dealership is going to: a) tell the owner s/he can buy the PCED and parts, and do the repairs themselves; or, b) write-up a repair estimate? Survey says....

Survey says ... Well, a quick search of the forum would have found references to it. As would reading the owner's manual of the vehicle. There is even an order form in the owner's manual for said service manuals. It doesn't get much easier to learn of its existance than that. If you had read the owner's manual you would have known this. The Ford dealer you went to was obviously misinformed. Did you even try another dealer or did you just give up and accept what the first dealer said? I've bought Ford service manuals from several dealers over the years and I've never had an issue like you have. So, yes, dealers do tell the owners about the manuals. I've even seen brochures for ordering the manuals in Ford dealer service departments. I guess you don't get around much????

When you consider "who" needs the information, it's usually new/inexperienced owners that don't even know the PCED exists, much less what the abbreviation stands for. Just look at the availability of the PCED versus the Service Manual on eBay.

The reason the forum exists is to help new user find the information and documentation they need. Is it a requrement that new users be aware of the PCED before they join the forum?

So, if someone is coming here posting requests for answers that have been previously answered and could be found using the search function, what's the likelihood they've going to show the initiative to research something they likely know nothing about, much less pay the subscription fee if they knew it was available? References to the various online manuals are posted in most parts stores, but I have as of yet to hear anyone ask about them, much less buy the actual subscription. Look at the link I posted to the free Autozone guides. They've been available for several years, yet I've never seen it mentioned here, prior to my post.

Is the PCED hard to come by - well, that's relative. It's an issue of people even knowing the online manuals exist (let alone the hardcopy), as well as people's willingness to pay for the online service - even when they do find out it exists. The availability of something you have no idea exists (especially when it's referred to out-of-context), is like someone asking you if you have an Uncle, that no one in your family has ever told you exists.

I get it know. We shouldn't mention the Ford manuals because some of us think they're hard to come by. Heaven forbid we should try to enlighten our fellow forum members. A quick search of the forum, btw, brings up no less than 41 threads containing "PCED". It's not that unheard of, after all, is it?

You actually pulled codes simply because you ran out-of-gas?


(sorry, you left yourself wide-open on that one... )

As a matter of fact, yes. I wanted to know what codes would be triggered by such an event. If you find that amusing, well, good for you.

 

[Mr Anonymous]

Enough.

I've never read so many long boring posts in my life, and the ***-for-tat is getting nowhere.

Thread closed.

Shorty, when you figure out what your problem is, or if you need further help, feel free to start a new thread.

My pancreas hurts.

 

[repoman88tc]

i`m having the same exact problem as Shorty, guess i`ll go to my long time ford mechanic,( now independent shop owner) and see if he can pin this down. mine "95 mtx" 3.0 is drinking fuel and hard to start throwing 172 at me running lean etc., runs like **** at wot seems to run okay mostly but may run better, just got this one. let`s solve this prob!!!!

 

[repoman88tc]

found my problem, o2 sensor on exhaust bank 1 was a 4 prong connector and it was supposed to have the 3 prong connector. in otherwords someone put the wrong o2 sensor on the car before i got it.