How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Don 'Mo Lurch' Your Own Que...
Don 'Mo Lurch'
Don 'Mo Lurch', Auto Mech / Electronics
Category: Chevy
Satisfied Customers: 20597
Experience:  Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.
Type Your Chevy Question Here...
Don 'Mo Lurch' is online now
A new question is answered every 9 seconds

2007 chevy cobalt ss: the crankshaft position sensor..reprogram..kit

Resolved Question:

replaced the crankshaft position sensor on my 2007 chevy cobolt ss supercharge no the car will not start do you need to reprogram the computer and also i have a stage 2 kit that was installed do you need to reprogram that also
Submitted: 7 years ago.
Category: Chevy
Expert:  Don 'Mo Lurch' replied 7 years ago.


Whenever Crankshaft Position Sensor is replaced:
Perform the CKP system Variation Learn Procedure


Install a scan tool.
Monitor the ECM for DTCs with a scan tool.
If other DTCs are set, except DTC P0315, refer to Diagnostic Trouble Code (DTC) List - Vehicle for the applicable DTC that set.

With a scan tool, select the CKP system variation learn procedure and perform the following:
Observe the fuel cut-off for the applicable engine.
Block the drive wheels.
Set the parking brake.
Place the vehicle's transmission in Park or Neutral.
Turn the air conditioning (A/C) OFF.
Cycle the ignition from OFF to ON.
Apply and hold the brake pedal for the duration of the procedure.
Start and idle the engine.
Accelerate to wide open throttle (WOT). The engine should not accelerate beyond the calibrated fuel cut-off RPM value noted in step 3.1.

Release the throttle immediately if the value is exceeded.

Important: While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate.

The engine control is returned to the operator and the engine responds to throttle position after the learn procedure is complete.
Release the throttle when fuel cut-off occurs.
The scan tool displays Learn Status:

Learned this Ignition.

If the scan tool indicates that DTC P0315 ran and passed, the CKP variation learn procedure is complete.

If the scan tool indicates DTC P0315 failed or did not run, refer to DTC P0315.

If any other DTCs set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for the applicable DTC that set.

Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.




Customer: replied 7 years ago.
the car will not start it will crank over but not start do you have to do this with the car running.
Expert:  Don 'Mo Lurch' replied 7 years ago.


You will need to scan for Trouble Codes first
Clear the Trouble Codes & then check for the starting issue.
Could be Security, Crank Sensor, Spark, Fuel, etc.



Customer: replied 7 years ago.

you can clear the code even if it does not start. right now the car is a the dealer it is not under warranty . also do you need to reflash for the stage 2 or does this take care of both when it is relearned.

Expert:  Don 'Mo Lurch' replied 7 years ago.


Use of Scan Tool should do both as long as the stage 2 is accepted by Computer

Customer: replied 7 years ago.
my problem is that now dealer was even able to find out that it need this crank sensor they had put a fuel pump in last year. we also replaced the throttle body because the throttle sensor also came up. that worked out fine ,could it also be because we replaced two sensors that day
Expert:  Don 'Mo Lurch' replied 7 years ago.


If it was running before you replaced the 2 sensors & now it is not
It could be the Sensors, esp[ecially if you used another brand other than GM Parts.
Trouble Codes should have been read prior to any other repair when the problem started

Customer: replied 7 years ago.
the car was running when the throttle boby was installed everythig was find it was when the crank sensor was installed , both parts i bought from GM . they even checked the harness and it was fine then we put back the old crank sensor to see if the new one was bad it still did not start.
Expert:  Don 'Mo Lurch' replied 7 years ago.


Use of scan tool should be able to find the problem & testing of the different circuits & modules will be needed.
If it never started after the Sensor was installed, Sensor could have crack when installed, Reluctor could have been damaged, Security System, Fuel Pressure, etc.



Customer: replied 7 years ago.
so is there more damage
Expert:  Don 'Mo Lurch' replied 7 years ago.


at this point, from what you are describing, it could be as simple as clearing Trouble Codes & getting engine to start, then program Sensor/s.
It can be something serious as the reluctor, but this should be able to be seen by Scan Tool when testing

Customer: replied 7 years ago.

so what you are saying that the code need to be cleared and then the car should start .then if not the computer needs to be reflashed. I just don't want this dealer to hand me a story. This car is a nightmare

Expert:  Don 'Mo Lurch' replied 7 years ago.


Trouble Codes need to be displayed, checked, problem fixed, before clearing Codes.
Start vehicle, program Sensor/s

Customer: replied 7 years ago.
thank you for all your help wish you were working on this car . at least i have a better idea when the come back to me with what they find but i know they will not like that I am going to question them with the information that you gave me after all I am a female they realy hate being second guessed do not under stand they make proformance cars and they do not know how to find these problems. thank you again.
Expert:  Don 'Mo Lurch' replied 7 years ago.


I understand....................sorry for the trouble.
Most Dealers will do it straight & try not to go overboard

Don 'Mo Lurch' and other Chevy Specialists are ready to help you

Related Chevy Questions