Crankshaft position sensor question?

[Phantom_WS6]

I am having a problem with the ignition. THe car won't start. I put in a new ICM, new spark plugs and new wires and still the car won't start. I'm getting no spark and no fuel. I also put in a new camshaft position sensor.

Can the crankshaft position sensor be bad and stop both spark and fuel coming to the motor? And when changing it, does the learn procedure have to be done or it doesn't matter?

And if it's not this, what are the signs of a dead PCM?

This is on a 2001 Camaro 3.8

Thanks in advance.

[3.4grapeofwrath]

Re: Crankshaft position sensor question?

Are you getting any codes?

[Phantom_WS6]

Re: Crankshaft position sensor question?

No codes. The car cranks and won't start. Before that I was getting a p0300 random cylinder misfire code, but after deleting the codes with a hypertech power programmer, I am getting no codes and the car won't start.

[Mark42]

Re: Crankshaft position sensor question?

If you change the crankshaft position sensor, the PCM needs the Learn proceedure. It will run without it, but not as well as with it.

[Bird_Of_Prey]

Re: Crankshaft position sensor question?

No codes. The car cranks and won't start. Before that I was getting a p0300 random cylinder misfire code, but after deleting the codes with a hypertech power programmer, I am getting no codes and the car won't start.

Have you pulled a plug wire to verify spark? Have you checked pressure at the rail? All fuses good? Fuel pump come on with the key?

[Bird_Of_Prey]

Re: Crankshaft position sensor question?

If you change the crankshaft position sensor, the PCM needs the Learn proceedure. It will run without it, but not as well as with it.

Just curious, but on my LS1, it runs fine without the Cam Position sensor functioning. I know all it does on the LS1 is verify BDC and TDC to figure out the firing order, with no adjustability.

[Phantom_WS6]

Re: Crankshaft position sensor question?

How would I perform the learn procedure? What tool do I need for it?

[Mark42]

Re: Crankshaft position sensor question?

Just curious, but on my LS1, it runs fine without the Cam Position sensor functioning. I know all it does on the LS1 is verify BDC and TDC to figure out the firing order, with no adjustability.

Don't know about LS1, but on the V6 the learn proceedure lets the pcm learn variance / tolerances built into engine and it can compensate accordingly. When I installed a mail order tuned PCM (not my original PCM) the Lean had to be done then too. It was easy to tell the difference before / after the Learn.

How would I perform the learn procedure? What tool do I need for it?

I called 4 or 5 different GM dealerships and talked to the shop manager. The one who knew exactly what I was talking about is the one I went to. (you would be surprised how many had no clue what the LEARN was about or how to do it). They took about 15 minutes total, including pulling the car into the shop, and charged me about $40 for the service. To me it was well worth the price.

They used a small hand held scanner type tool. The car is started, held at various RPM's for a few seconds each, as the PCM leans the variance at that RPM. The info is saved in the PCM, and is not lost even when a fresh tune is loaded.

BTW, one manager told me it was a very complicated procedure and the car had to be left overnight! LOL!

From GM Service Information for the 3.8 V6:

Service InformationCKP System Variation Learn Procedure

Crankshaft Position System Variation Learn Procedure

The crankshaft position system variation compensating values are stored in the PCM non-volatile memory after a learn procedure has been performed. If the actual crankshaft position system variation does not match the crankshaft position system variation compensating values stored in the PCM, DTC P0300 may set (refer to Diagnostic Aids for DTC P0300).
The Crankshaft Position System Variation Learn Procedure should be performed if any of the following conditions are true:

• DTC P1336 is set.
• The PCM has been replaced.
• The engine has been replaced.
• The crankshaft has been replaced.
• The crankshaft harmonic balancer has been replaced.
• The crankshaft position sensor has been replaced.

Caution

Before performing the Crankshaft Position System Variation Learning Procedure always set the vehicle parking brake and block the drive wheels in order to prevent personal injury. Release the throttle immediately when the engine starts to decelerate in order to eliminate over revving the engine. Once the learn procedure is completed, the control module will return engine control to the operator and the engine will respond to the throttle position.


Important

Begin the crankshaft position system variation learn procedure with the ignition switch OFF. Do not turn ON the ignition switch or start the vehicle unless instructed to do so by the scan tool.
The scan tool crankshaft position system variation learn function will be inhibited if any powertrain DTCs other than DTC P1336 are set before or during the crankshaft position system variation learn procedure. Clear DTCs before attempting to perform the crankshaft position system variation learn procedure. If any DTCs reset, the DTCs must be diagnosed and repaired before the crankshaft position system variation learn procedure can be sucessfully completed.
The crankshaft position system variation learn function will be inhibited if the PCM detects a malfunction involving the camshaft position signal circuit, the 3X reference circuit, or the 18X reference circuit.

• If the scan tool indicates that a problem with the camshaft position signal exists, refer to DTC P0341 Camshaft Position (CMP) Sensor Performance .
• If the scan tool indicates that a problem with the 3X crank signal exists, refer to DTC P1374 Crankshaft Position (CKP) High to Low Resolution Frequency Correlation .
• If the scan tool indicates that a problem with the 18X crank signal exists, refer to DTC P0336 Crankshaft Position (CKP) Sensor Circuit .

The scan tool crankshaft position system variation learn function will not be enabled until engine coolant temperature is greater than 70° C (158° F).
Selecting the crankshaft position system variation learn procedure on the scan tool will command the PCM to enable CKP system variation learn fuel cutoff and allow the crankshaft position system compensating values to be stored in the PCM. The PCM must detect an engine speed of 5150 RPM (CKP system variation learn fuel cutoff) during the crankshaft position system variation learn procedure to store the crankshaft position system compensating values and complete the procedure.

1. Set the parking brake.
2. Block the drive wheels.
3. Close the hood.
4. Start the engine and allow engine coolant temperature to reach at least 70°C (158°F).
5. Turn OFF the ignition switch.
6. Select and enable the crankshaft position variation learn procedure with the scan tool.
7. Start the vehicle
8. Ensure that the transaxle is in Park.
9. Apply and hold the service brake pedal firmly.
10. Increase accelerator pedal position until CKP system variation learn fuel cutoff is reached. CKP system variation learn fuel cutoff is reached at 5150 RPM. Immediately release the accelerator pedal when fuel cutoff is reached.
11. The crankshaft position system variation compensating values are learned when RPM decreases back to idle. If the procedure terminates, refer to Important above for instructions.
12. Observe DTC status for DTC P1336.
13. If the scan tool indicates that DTC P1336 ran and passed, the crankshaft position system variation learn procedure is complete. If the scan tool indicates DTC P1336 failed or not run, check for other DTCs. If no DTCs other than P1336 are set, repeat the crankshaft position system variation learn procedure as necessary.

[ssms5411]

Re: Crankshaft position sensor question?

X2 on a Crankshaft Relearn procedure. Need to be done if you have replaced the balancer , crankshaft sensor or a new PCM that hasn't been programed. Camshaft sensors can be replaced with no problems just swap them out and your good to go. Hptuners has it where you can do a relearn procedure and takes you through the steps. My Aeroforce scanner gauge has a case relearn procedure also that takes you through the steps also.

[Phantom_WS6]

Re: Crankshaft position sensor question?

If the crankshaft sensor is faulty, can it stop spark and fuel at the same time?

[Bird_Of_Prey]

Re: Crankshaft position sensor question?

Don't know about LS1, but on the V6 the learn proceedure lets the pcm learn variance / tolerances built into engine and it can compensate accordingly. When I installed a mail order tuned PCM (not my original PCM) the Lean had to be done then too. It was easy to tell the difference before / after the Learn.



I called 4 or 5 different GM dealerships and talked to the shop manager. The one who knew exactly what I was talking about is the one I went to. (you would be surprised how many had no clue what the LEARN was about or how to do it). They took about 15 minutes total, including pulling the car into the shop, and charged me about $40 for the service. To me it was well worth the price.

They used a small hand held scanner type tool. The car is started, held at various RPM's for a few seconds each, as the PCM leans the variance at that RPM. The info is saved in the PCM, and is not lost even when a fresh tune is loaded.

BTW, one manager told me it was a very complicated procedure and the car had to be left overnight! LOL!

From GM Service Information for the 3.8 V6:

Same procedure for the LS1. I'm setting P0341 Cam Position Sensor due to a break in the harness. I ran my best time with no learn, lol.

[ssms5411]

Re: Crankshaft position sensor question?

If the crankshaft sensor is faulty, can it stop spark and fuel at the same time?

I think it would stop spark for sure , just becuase it wouldn't be in firing order same for the injectors so I guess it could take out both since they wouldn't be correct , be like #6 cyl. firing with fuel when #1 cyl. is suppose to , not good. LOL

[Phantom_WS6]

Re: Crankshaft position sensor question?

Ok. Some wire going to the crankshaft sensor had a break in it and it is fixed now. The car starts. Now I'm back to the problem I had in the first place.

When I start driving, let's say I'm going 20-30 mph, I hit the gas and I can feel the motor shake for a few secs and the car won't accelerate and then it starts accelerating, while in the meantime the check engine light blinks and then it turns off. I suppose there is a misfire?

The car has new spark plugs and wires, new ICM, new camshaft position sensor and new crankshaft position sensor.

Could this misfire be due to an injector?

[ssms5411]

Re: Crankshaft position sensor question?

You need a case relearn done on your car for it to run , its running like I said before the PCM doesn't know the order to fire the injectors and spark , running it like you are is only going to lead to a blown engine. Find a dealer or a shop can do a case relearn.

[Phantom_WS6]

Re: Crankshaft position sensor question?

The thing is that the car did this before I changed all of those things. After changing them, it has continued.. And I cant find a dealer or a shop to do it because I am in Europe with the car. How can I do it myself? What do I need for it? All I have for the car is a Hypertech Power Programmer.