Engine Codes and Problems

[JimN696]

Engine Codes and Problems SD Patt, remember me?

I haven't posted in a while, but I have been having some problems with my 94 ATX with about 96K on it. Every once in a while for the past year after a full throttle run, the check engine light would come on. It happened so infrequently, I ignored it. Last week I cleaned my K and N panel filter and re oiled it. A few days later, I started the engine cold and made a short trip to the store. The check engine light came on. I shut off the engine and tried to restart it, but it wouldn't start. After I cranked for a few seconds a few times, it started, but ran very rough and the tachometer was dead. The check engine light was on again. I shut it down, went in the store and did some shopping. When I came out the car started right up and ran fine. The tach started working within a few minutes, but the check engine light comes on more often now. I took the car to my local Ford dealer. No one there really knows these cars, but they read the codes for me. This is what they got: 176, 212, 214. The dealer couldn't really interpret these so I went on a website and got these answers: 176: O2 sensor not switching; system is or was lean; left or front. 212: Ignition tach signal was erratic (module, wiring) or Spout circuit fault. 214: Error in cylinder ID (CID) circuit or signal.
So what does it all mean? I understand the O2 code and it probably is due to a failing sensor but what is the spout circuit? The tech at Ford told me that the 214 error may mean a faulty cam position sensor. Is that true and is there a way to check it if it's faulty. What will happen if I don't fix it? Thanks for the help, folks.

 

[SHOhhhhMan!]

Yep, sounds like you need a new Cam Position Sensor. I had the exact same problem on my 89 T-Bird SC (which has almost the exact same DIS ignition system as the SHO). The tach would die and the car would either die or start bucking and wouldn't want to start afterwards. Here, let's get an understanding of how the Ford EEC-IV DIS ignition system works so you can understand why it's doing what it's doing...

The EEC-IV DIS uses a wastespark system, which is why you have one ignition coil per 2 cylinders. The way the car determines when to fire each pair of plugs is accomplished through the use of two hall-effects sesnors; one on the crank pulley and one in the place where the distributor used to go. Pretty much they way it works is the CPS (Crank) is mounted so a shutter wheel of vanes and windows on the back of the crank pulley passes through and air gap and excites the hall-effect crystals in the sensor. The crank pulley has 3 windows and 3 vanes (each covering 60* of rotation) that determine when each cylinder is approaching TDC and initiate the saturation of the coil for that pair of companion cylinders. Can the car run with just this sensor? Yes. However, it doesn't run for long. The CMP (Cam Pos) is there for this reason. This is much like the CPS, however instead of 3 vanes and 3 windows, there just 1 vane and 1 window that each occupy 180* of the rotation on the gear that is run off the camshaft. The purpose of this sensor is to allow the DIS module to know where cylinder #1 is at TDC so it can fire the coils in the correct order. When the CMP fails, the car basically just fires the coils at random until it gets lucky and gets it right. This is why the car doesn't want to start or takes more cranking than normal.

When the DIS Module doesn't get a signal from the CMP, it will default the timing to 10* BTDC since it gets put into FMEM (Failure Management Effects Mode). This may be what is causing the Code 212 because the normal Spark Output or SPOUT is usually 26* BTDC, but FMEM has ******** SPOUT to 10* BTDC.

So, long story short. Spend $50, replace your cam position sensor and that should take care of your problem. If not, the next component at fault is likely the CPS.

 

[AutoSHO]

Sounds like a bad cam sensor. Also, replace the oxygen sensors as a pair, the other isn't far behind.

 

[Rockledge]

... Here, let's get an understanding of how the Ford EEC-IV DIS ignition system works so you can understand why it's doing what it's doing...

The EEC-IV DIS uses a wastespark system, which is why you have one ignition coil per 2 cylinders. The way the car determines when to fire each pair of plugs is accomplished through the use of two hall-effects sesnors; one on the crank pulley and one in the place where the distributor used to go. Pretty much they way it works is the CPS (Crank) is mounted so a shutter wheel of vanes and windows on the back of the crank pulley passes through and air gap and excites the hall-effect crystals in the sensor. The crank pulley has 3 windows and 3 vanes (each covering 60* of rotation) that determine when each cylinder is approaching TDC and initiate the saturation of the coil for that pair of companion cylinders. Can the car run with just this sensor? Yes. However, it doesn't run for long. The CMP (Cam Pos) is there for this reason. This is much like the CPS, however instead of 3 vanes and 3 windows, there just 1 vane and 1 window that each occupy 180* of the rotation on the gear that is run off the camshaft. The purpose of this sensor is to allow the DIS module to know where cylinder #1 is at TDC so it can fire the coils in the correct order. When the CMP fails, the car basically just fires the coils at random until it gets lucky and gets it right. This is why the car doesn't want to start or takes more cranking than normal.

When the DIS Module doesn't get a signal from the CMP, it will default the timing to 10* BTDC since it gets put into FMEM (Failure Management Effects Mode). This may be what is causing the Code 212 because the normal Spark Output or SPOUT is usually 26* BTDC, but FMEM has ******** SPOUT to 10* BTDC...

Good stuff, nice summary of how the DIS system uses the crank and cam sensors...

 

[JimN696]

Thanks for the replys. SHOhhhhMan!, your reply was great because it explained how the system works and what the codes actually mean. One of my sons works at a Ford dealer and the techs there really didn't know how to diagnose the problem. The tech who read the codes was pretty green and he said that "These cars were going out just as I was coming in and we never really worked on many of them anyway..." The guy gave me an educated guess about the cam sensor problem that turned out to be right, but they didn't know what the 212 code meant. My next question is whether or not I should drive the car until I get it fixed. It seems to run fine now. I have to go on a short trip into NYC with it this weekend and I don't want to break down and get stuck in that madhouse. Thanks again. I hope to post some pics of my ride here soon.

 

[projectSHO89]

You can unplug the cam sensor and run it that way. I did that last summer for a couple of weeks until I got around to replacing it.

The engine will usually take multiple attempts to start, the CEL will be on, and you will have no TACH while in this mode.

The Cam sensor is about $30 from AutoZone and can be replaced in 30 minutes or so. You will need a 1/4" drive socket set that includes either a 5.5 mm or a 7/32" socket.

Steve

 

[JimN696]

One more question

I have another question regarding the oxygen sensors. My Ford Dealer parts dept says there are two different part numbers for the sensors. Is there any way to tell which ones are for my car?

 

[projectSHO89]

Just get the Bosch one from AutoZone. Don't bother with the dealer.

Steve

 

[SHOhhhhMan!]

I have another question regarding the oxygen sensors. My Ford Dealer parts dept says there are two different part numbers for the sensors. Is there any way to tell which ones are for my car?

I've never really looked into O2 sensors on my SHO so I'm not positive but here's what I'm going to speculate; one part number may be for a heated O2 and the other for the non-heated one. From what I've seen with Ford EEC-IV DIS, they've always used a heated O2 sensor, even on my 89 T-Bird SC. Now, the regular Taurus which doesn't have a DIS probably just uses the non-heated O2. Eiter that or they might they might have changed the heated O2 design for the SHO from a 3-wire to 4-wire or visa versa between gen 1s and gen 2s. I'd check around online and see what you can find.

Oh! BTW, it may sorta sound like it, but I'm not really much a tech yet, but I'm going to college for it. I've got a whole bunch of 500-1000 page books full of automotive jargon, schematics, and other crap that no one else but technicians really wants to read.

 

[twr]

My recollection is that the difference is the ATX vs. MTX cars. MTX is a 3 wire and ATX is a 4 wire.

 

[JimN696]

oil in sensor cavity

Well I managed the cam sensor replacement and the car runs better than ever. When I removed the sensor, there was a little bit of oil in the cavity; is this normal or should it be cause for concern?

 

[projectSHO89]

The camshaft seal is leaking.

Steve

 

[SonicRiot]

Don't buy Bosch replacement O2 sensors from AutoZone. They tend go south MUCH faster than the stock Motorcraft ones. This goes with all cars. O2 sensors cannot increase or enhance performance, so always get the stock replacement ones from the dealer. They last longer and will always be more accurate for a specific vehicle.

Besides, Bosch tends to make some crappy stuff... like their O2 sensors.