Q&A

We completed the "crank's does not start" checklist. Completed entire ignition control checklist. Completed all the PCM ground checklists 1 and 2. Tightened every terminal around the ICM. Tightened all of the connections on the PCM. Good voltage and ground at the PCM. Good wire/good plugs. Battery is at full voltage. ICM put on was used from a 1999 Aurora, with 111,000 miles. Every time I disconnect the ICM, I hear the injectors pulse anytime the ignition is on. All fuses are good, PCM and ignition. There are no codes. There's no tachometer output and no spark when I try to start the car.

what is the fuel pressure? the crank sensor is the controller of firing the injectors. usually when there is no tach reading on cranking, it is narrowed down to the crank sensor are. that is, harness sensor, and toner ring.

Roy

We have checked all of the wires from the ICM to the connector side of the PCM and they all have less than 5 Ohms of resistance. WE have checked all of the wires from the crank sensors up to the PCM harness side, those all had less than 5 Ohms resistance. We checked the crank shaft position sensors and they had around 1000 Ohms on both of those sensors. We checked the cam shaft position sensor wires for resistance and those were less than 5 Ohms. The cam shaft position sensor had around 1100 Ohms resistance. I put test light between terminals A and C of connector C3 at the IC module, and that lit. We've verified that the sensors, the wires, and the ICM are all good.

Well, this morning my son changed the wiring harness and the car started. He's driving it around now to see if it will again mysteriously stop.

Thanks for helping us narrow down the area in which to test and retest.
LA