Quote:
Originally Posted by Schrade
Good diagnostic work...
Shouldn't there have been a DTC for CP Sensor? Even a History DTC, for out of spec parameter?
|
There wasn't any DTC's logged or in history. From my understanding there isn't a specific code for the CP sensor. The two codes that deal with electronic ignition appear to be DTC 42 (Ignition Control Timing Circuit) and DTC 36 (Electronic Ignition Circuit Missing).
The fault tree for DTC 42 has to do with timing above and below 400 rpm and the ECM, ICM, and ignition control (IC) signal. A 42 is set when IC mode isn't demanding a bypass of the system (like it should be), the ECM doesn't detect a IC pulse or no IC pulse detected by the ICM.
Similar to DTC 42, DTC 36 is engine timing in ignition control (IC) mode enabled at over 400rpm, or the ICM is not seeing the IC signal from the ECM or the ECM is not detecting the correct voltage on it's fault line to the ICM.
Neither DTC technical description or fault tree make reference to the high or low input from the crankshaft sensor either.
From my readings of the system design, I simply think it was a case of the sensor slowly packing it in... until it finally broke (open circuit) once and for all.
Here is my theory on this whole ordeal:
The occasional hot
no start:
- The heat from the engine running and then shutting off was perhaps was causing some minor expansion or contraction with the sensor to cause a open circuit
- That OC obviously effected the ICM's ability to determine engine speed or crankshaft location. Without that, the ICM can't send a reference signal to the ECM and the ECM doesn't know which coil to fire.
- For some reason the sensors wiring corrected itself enough for the ICM to get a sync pulse and then she'd fire
Suddenly quit while running:
- Similar to above, the sensor would open up from heat or something
- Once it opened, the ECM doesn't know if the engine is running, so it cuts the injectors and therefore kills the car....then restart results in my first bullet list
No start:
- Sensor packed it in finally...
- Refer to first post
Truth be told, I'm actually grateful that she got me home. I was down in Montana on a road trip about 1000km or so away from home, in a different country no less. I had experienced those no starts while I was in Montana, but it eventually fired every time. I had finally got back into Canada and was1.5 blocks away from the house, the car quit again and I was able to coast right up to the alley way...then it was dead in the water for good.
BUT it got me home....just something to be said there.
