Crankshaft Position Sensor

[rjk185]

I had a crankshaft position sensor replaced in July of 06 due to a Check engine lite. I have another check engine lite and the code is p0335,
"The PCM has determined that a malfunction exists in the electrical circuit for crankshaft position sensor "A".

In july they replace the sensor, Is there more going on and if the sensor is bad how can determine. The dealer ship has since gone out of business????

Its got over 100k, runs great, is it a real problem????

[GTP Dad]

Welcome to AF!!

Try clearing the code and see if it returns. If it does check the wiring on the connector to the CPS. Sometimes they will corrode. Also check the wiring above the CPS connector. You may have a wire that is worn and making contact with the block. It is also possible that the CPS is bad again.

[rjk185]

Originally Posted by GTP Dad

Welcome to AF!!

Try clearing the code and see if it returns. If it does check the wiring on the connector to the CPS. Sometimes they will corrode. Also check the wiring above the CPS connector. You may have a wire that is worn and making contact with the block. It is also possible that the CPS is bad again.

I did get it cleared and it came back after the second start? Where do I find the sensor and wires?

[MT-2500]

Originally Posted by rjk185

I did get it cleared and it came back after the second start? Where do I find the sensor and wires?

Here is the test to run.
http://members.troublecodes.net/crunch/355.pdf

What year and engine size and mileage?
3.5 will be on lower left engine block
Did you use a good OEM type sensor or a el chepo?

[Jimmy Olsen]

Originally Posted by rjk185

I had a crankshaft position sensor replaced in July of 06 due to a Check engine lite. I have another check engine lite and the code is p0335,
"The PCM has determined that a malfunction exists in the electrical circuit for crankshaft position sensor "A".

In july they replace the sensor, Is there more going on and if the sensor is bad how can determine. The dealer ship has since gone out of business????

Its got over 100k, runs great, is it a real problem????

If you got it repaired at a GM dealership, I would expect that GM would warrant it for 15k miles or 1 year. Is there another GM dealership close to you?

[rjk185]

Originally Posted by Jimmy Olsen

If you got it repaired at a GM dealership, I would expect that GM would warrant it for 15k miles or 1 year. Is there another GM dealership close to you?

Good idea, I'll give it a try.

[bwashin]

I have the same car, same problem ---over 100K miles. I have the 3.5L engine where the CPs is lovated on the side of the engine block above the starter and behind the header.

In my case the engine misfires concurrently with the Fault Code and CHeck Eng9ine light appearing. I get a cylynder 2 misfire right afterb the P0335 code for the CPS electrical circuit.

I looked and noticed that the wiring just next tot he connector for my CPS sensor had severe heat damage (nice design right next to the headers), so I will be replacing the connector with a new connector and pigtail and reworking the heat shielding to better protect the wiring.

It would probably be prudent to go ahead and replace the sensor while I am in there, but I suppose no one knows anything about the "LEARN PROCEDURE" that is suposed to be performed after replacing the sensor? Is this somthing that can be done without a code reader or programming tool?

[MT-2500]

Originally Posted by bwashin

I have the same car, same problem ---over 100K miles. I have the 3.5L engine where the CPs is lovated on the side of the engine block above the starter and behind the header.

In my case the engine misfires concurrently with the Fault Code and CHeck Eng9ine light appearing. I get a cylynder 2 misfire right afterb the P0335 code for the CPS electrical circuit.

I looked and noticed that the wiring just next tot he connector for my CPS sensor had severe heat damage (nice design right next to the headers), so I will be replacing the connector with a new connector and pigtail and reworking the heat shielding to better protect the wiring.

It would probably be prudent to go ahead and replace the sensor while I am in there, but I suppose no one knows anything about the "LEARN PROCEDURE" that is suposed to be performed after replacing the sensor? Is this somthing that can be done without a code reader or programming tool?

Always better to start a new thread with another car or problem.
On your 3.5 I have saw a few bad sensors even on low mileage ones.
I would replace the sensor with OEM dealer part at the same time.
Your PCM should relearn on it own on that one.

[bwashin]

Thanks! I do plan to go ahead and replace the sensor. It was difficult finding an AC-delco replacement connector and pigtail, but I finally did. I managed to find the actual learn procedure on the web as well. So, if the PCM didn't learn it on its own, or had some other issue, I could always rent an ODBII tool and run the procedure myself...it looks pretty simple. My main concern now is passing the emissions testing we have to do around here, and thats why i am afraid I might have to run that procedure to clear the old faults. We can't renew our car tags without passing that test. I'm sure replacing both the harness and the sensor will take care of the issue, but if you have any suggestions about what it takes to "officially" clear those faults (not just extiguish the light), it would be much appreciated. Sorry about using the old thread. I'm a little new to this.

[MT-2500]

Originally Posted by bwashin

Thanks! I do plan to go ahead and replace the sensor. It was difficult finding an AC-delco replacement connector and pigtail, but I finally did. I managed to find the actual learn procedure on the web as well. So, if the PCM didn't learn it on its own, or had some other issue, I could always rent an ODBII tool and run the procedure myself...it looks pretty simple. My main concern now is passing the emissions testing we have to do around here, and thats why i am afraid I might have to run that procedure to clear the old faults. We can't renew our car tags without passing that test. I'm sure replacing both the harness and the sensor will take care of the issue, but if you have any suggestions about what it takes to "officially" clear those faults (not just extiguish the light), it would be much appreciated. Sorry about using the old thread. I'm a little new to this.

A code clear will clear faults. But it will not pass emissions untill PCM resets.
And fault code will come back unless you fix the problem.
Fix the problem and clear codes and drive until the PCM reset and you are ready for emissions test.

[rjk185]

Originally Posted by MT-2500

A code clear will clear faults. But it will not pass emissions untill PCM resets.
And fault code will come back unless you fix the problem.
Fix the problem and clear codes and drive until the PCM reset and you are ready for emissions test.

How do I know the PCM is reset?

[MT-2500]

Originally Posted by rjk185

How do I know the PCM is reset?

When a scanner says it passes the readines moniter test.

[bwashin]

Is it correct to say that completion of the GM drive cycle will reset the PCM, though? I have heard that normal driving of about 150 miles after fixing the problem will usually complete the drive cycle and cause the reset. I haven't tried it, but the exact directions for intentionally performing the GM Drive Cycle are posted on http://www.OBDII.com/

[watchdog39]

It is a pain in the neck and requires some open road but if you have the codes cleared there is a 12 min proceedure to reativavte the system and it does work I have used it a few times. Here it is! Put the car in drive and let idle with rear defrosters and AC on for 2.5 min, Then turn off AC and at 1/2 throttle accelerate to 55 MPH for 3 min., without breaking let the car drift to 20MPH, at 3/4 throttle acclerate to 60 MPH for 5 min., then drift to a stop. This will reset the computer system if you have cleared all the codes. The tricky part is open road with no traffic cause you cannot break at any point once you start to move although I have found that the sevice engine light comes back on while accelerating to 60 MPH indicating that it has reset and I yet still have something wrong.

[bwashin]

Thanks. I found that the easiest course was to just drive the car for 150 miles or so (which only took a week with my commute). Through normal driving it reset. Two weeks after i made the repair (just before the drop dead time I needed to pass the test), I pulled in for the emissions check and passed with flying colors. The hardest part about changing this sensor out was the unknowns about the condition of the car after making such a change. As it turns out, my concerns were unfounded. In retrospect the whole thing was a piece of cake. I spent more time worrying about the consequences of changing the sensor without programming tools, etc. than I did diagnosing and repairing the problem.