Engine/Transmission (1998.5 - 2002) Check engine light

[DWoodward]

I have a 99 2500 4 x 4 that has a check engine light on. I got a P0336 code which is a crankshaft positon sensor. Then the tach quit working and it would not restart. I just replaced the crankshaft position sensor and it starts, the tach works again, but the check engine light is still on. What do I do next?

 

[JLandry]

Sounds like you need to clear the trouble code from the ECM memory using a code scanner. Another option is to disconnect both batteries, turn on the headlight switch, then wait about 30 minutes. Turning on the headlight switch is supposed to help drain the memory of the ECM and PCM faster. Of course disconnecting the battery also clears your radio presets, etc.



After you turn off the headlight switch and reconnect the batteries, you'll need to reset the APPS (Accelerator Pedal Position Sensor) to the ECM. This is done by turning the ignition switch to the RUN position (don't start), then slowly push the accelerator pedal all the way to the floorboard and then slowly release it. Turn the ignition switch OFF and you're all done!



Good luck,



John L.

 

[DavidC]

The light should automatically reset after x amount of restarts without a fault. The actual number I do not remember but I think it is 3.



Dave

 

[JLandry]

The light should automatically reset after x amount of restarts without a fault.

Dave,



Just an FYI...



In most systems, it takes 3 good cycles (or what Chrysler calls "trips") to extinguish the MIL. Each trip has a specific set of conditions which must be met before it's considered complete by the PCM or ECM. Generally, and at a minimum, the engine must be started and run for at least 2 minutes without any faults occurring to count as one good trip. Some trouble codes have additional requirements which must be completed before a good trip is considered met.



Once 3 good trips have been completed, the MIL will turn off but the trouble code will remain stored in the ECM or PCM for a total of 40 "warm up" cycles before being self-extinguished. A warm up cycle is defined as: The coolant temp must cross 160 degrees F, the coolant temp must rise 40 degrees F, and no further faults occur.



A scan tool simply bypasses all this by forcibly clearing trouble codes regardless of the number of good trips.



Best regards,



John L.

 

[DavidC]

John, good info for people, I use the laptop with the OBD2 program to clear codes and engine monitoring. I just mentioned that it should clear itself if buying or finding someone with a scanner was not feasible.



Dave

 

[DWoodward]

Check engine light went off

Thanks for the replies. I guess I was just impatient, after a few more starts and a short test drive, the check engine light went off and has stayed off. Appreciate all the help.