What's up with these codes?

[cRaZySHO.]

I got a 116-Coolant temp. sensor out of range
and a 225-Knock sensor not tested
Any clue? I'm lost. These were found during the KOER test. Also, my KOEO test said that I have a Mass air flow signal that is too weak. Shoman94 said my mass air tube might have a loose hose clamp, but all of them were tight. I was thinking maybe my 73mm MAF without an LPM is giving this weak signal. Any help would help greatly. Thanks in advance.

 

[naval-avi8or]

Was the car in closed loop (ie normal operating temp.) if not that could explain the 116. Car has to be in closed loop to do the KOER test.

Did you accomplish the Dynamic response test (ie 1/2-3/4 throttle tap) I'm not 100% sure but I think thats were the knock sensor is tested.

<small>[ April 30, 2002, 07:29 PM: Message edited by: naval-avi8or ]</small>

 

[cRaZySHO.]

I think your right about the coolant code. I only had the car running for 3-4 minutes when I ran the test. But on my Snap-on scanner it prompts with code 10, which means snap throttle to 50%. I did that then it told me the final codes. And the knock sensor code was the second code on the list. I'm lost. My father who has been a mechanic for 32 years, can't figure this one out(I think it's because his time was when everything was carbureted, and nitrous came in a liquid to pour in your gas tank.).

 

[naval-avi8or]

Maybee the knocksensor failed to test because of the open loop. Heat her up real good and then retest.

 

[cRaZySHO.]

I'll have to try that later, it's pouring right now. I'll be sure to post as soon as I do.

 

[naval-avi8or]

Kinda sucks they didn't put that connector in the car like most do.

 

[sdpatt]

Read this description of the knock sensor code.

225 (R) Knock sensor not tested (ignore if not pinging)

The knock sensor only generates a signal when it detects a knock. If the engine does not generate a knock during the goose test (most often it does not), then the code will be displayed. This is only a problem if you have been hearing continuous knocking during certain engine operating modes. In other words, no worry, mate.

Regarding the MAF code, clear the codes, warm the engine to normal temp and run the test again to see if the code reappears.

<small>[ April 30, 2002, 09:47 PM: Message edited by: sdpatt ]</small>

 

[Shoman94]

sdpatt:
Read this description of the knock sensor code.

225 (R) Knock sensor not tested (ignore if not pinging)

The knock sensor only generates a signal when it detects a knock. If the engine does not generate a knock during the goose test (most often it dies not), then the code will be displayed. This is only a problem if you have been hearing continuous knocking during certain engine operating modes. In other words, no worry, mate. </strong>

Unfortunately this is incorrect. During the KOER test, the test advances the timing to create a ping so the sensor CAN detect it. If it doesn't it will throw the 225 code. You need to replace the KNOCK SENSOR. Below is the way it works.

PURPOSE
The Knock Sensor (KS) is used to sense ignition detonation (ping) and to supply this information to the Powertrain Control Module (PCM ). The PCM uses this input to optimize ignition timing while reducing the occurance of spark detonation and minimizing the amount of Oxides of Nitrogen (NOx ) produced in the exhaust.

CONSTRUCTION
The sensor has a thin circular piezoelectric ceramic disk that is bonded to a metal diaphragm. Electrical connections are made through a two pin integral connector.

OPERATION
The sensor is designed to resonate at approximately the same frequency as the engine knock (5-6 KHz). As the piezoelectric disk resonates it converts the sound vibration to an electrical voltage with an equal frequency. This signal is sent directly to the PCM.

The KS generates its own voltage and does not require a separate power supply. The PCM supplies the sensor ground through the SIG RTN circuit.

RELATED DIAGNOSTIC TROUBLE CODES

DTC 25/225 - KS signal was not sensed by the PCM during the Key On Engine Running (KOER ) self-test.

<strong> NOTE : During the dynamic response (snap throttle) portion of the KOER self-test the PCM advances the timing and checks for a corresponding output from the KS sensor. </strong>

As far as your ACT....Do like Naval and Scott said.

Now on your MAF issue...I missed that you had a 73mm. Since you don't have an LPM then yes I suppose it could cause the code but see that you were have the check engine lite on on full throttle acceleration only...none of the other codes have anything to do with that. That would mean if it was normal for the check engine light to come on due to the MAF beaing a 73mm then it would have happened from day-1 of installing your MAF. You could always install you 55mm MAF back and see what happenes to the code.

Jason

<small>[ April 30, 2002, 09:41 PM: Message edited by: Shoman94 ]</small>

 

[Shoman94]

Here is more on your 157 code....

Continuous Memory Diagnostic Trouble Code (DTC) 157 indicates the Mass Air Flow (MAF) sensor signal went below 0.4 volt sometime during the last 80 warm-up cycles.

Possible causes:

Poor continuity in MAF sensor harness or connectors.

Intermittent open or short in MAF sensor or harness.

Damaged MAF sensor.

Idle Air Control (IAC) system failure (at closed throttle position).

Do this to retest......

Clear continuous memory.
Start engine and idle for 5 to 10 minutes.
Vehicle in "NEUTRAL". (Set park brake)
Suddenly goose (greater than a half second) the throttle, approaching 1500 rpm.
Allow to return to idle.
Then, goose the throttle again, approaching 1500 rpm.
Allow to return to idle, shut the car off.

ReRun KOEO Self-Test to observe Continuous Memory DTCs.

Let me know if it reoccurs.....

Sorry I didn't respond to your last post you created....I guess I missed it.

Jason

<small>[ April 30, 2002, 09:38 PM: Message edited by: Shoman94 ]</small>

 

[sdpatt]

What I wrote was, "If the engine does not generate a knock during the goose test (most often it does not), then the code will be displayed." If the knock event is not created, the sensor's operation cannot be confirmed. I have seen more than one code description indicating that this is a possibility.

I replaced the knock sensor in my engine because I was noticing a great deal of pinging at light throttle acceleration. After the installation of the new sensor, the pinging was gone, so the new sensor was doing its job, but the knock sensor code was not generated during a subsequent goose test. To repeat, as long as your engine is not experiencing a great deal of pinging, your knock sensor is probably working just fine.

Scott

 

[Shoman94]

sdpatt:
What I wrote was, "If the engine does not generate a knock during the goose test (most often it does not), then the code will be displayed." If the knock event is not created, the sensor's operation cannot be confirmed. I have seen more than one code description indicating that this is a possibility.

I replaced the knock sensor in my engine because I was noticing a great deal of pinging at light throttle acceleration. After the installation of the new sensor, the pinging was gone, so the new sensor was doing its job, but the knock sensor code was not generated during a subsequent goose test. To repeat, as long as your engine is not experiencing a great deal of pinging, your knock sensor is probably working just fine.

Scott

I made a note of your experience...good to know. (No pun intended)

Although on the other end.....I doubted my knock sensor also...but I installed the breaker box and tested the KS at pin point and it did fail. IMO if the code is generated then replace it. In the event the motor does ping....I would want my KS to work correctly.

Jason

 

[cRaZySHO.]

Shoman94, do you think the 157 code possiblity of being the open or short in MAF relay be related to me interupting the MAF signal with the A'pex? I have never had a CEL before now that is related to my MAF. But some people on the forum told me that eventually our cpu's will learn the corrections I have made with the A'pex, and will try to correct them. I'm thinking now that the light is on, the cpu is now learning that there is an odd or unfamiliar signal coming from the MAF, and is trying to correct it. Or it can't correct it and that is why the light is coming on. But, Sdpatt and Shoman94, thank you very much for your priceless info. Later guys.