Hopefully my clever title hooked you to read this. 
Let's start at the beginning. The drivetrain from this car is transplanted from the car that I wrecked back in 2003. So, the wiring harness in question throughout this ordeal came on the roller I purchased. Before this transplant I never had any issues with the cam sensor.
Without getting into every little detail of the story, I ended up with a code 41. I have since changed the cam sensor cap, the metripack connector for the cam sensor, the C3I module, and the harness connector for the C3I module. So I've been through 2 cam sensor caps, 2 ECMs, and 3 C3I modules. I've also made sure to get good metal to metal connection through the brackets that hold the C3I module to ensure a proper ground. Oh and I forgot to mention I ohmed out the wires that run from the cam sensor to the C3I connector and they check out OK.
So, I'm down to suspecting the wire that runs from the C3I to the ECM. I checked the ECM pin and the plug that goes into the ECM. Physically, they both look OK.
I need to find a way to check the wire itself or at least monitor that wire to see what the ECM is seeing. I was hoping someone would be able to tell me what I need to look for when I backprobe that pin. An old GM tech friend of mine said he wasn't sure but it's probably a 5v square wave that is being sent to the ECM.
So can someone tell me what to look for here? I doubt I can get access to an oscilloscope but it's not entirely out of the question. If I check it with voltmeter what should I see? What is the ECM looking for? Exactly what conditions have to be met for the ECM to trigger the code? I assume either voltage out of range or incorrect voltage to this pin over a certain amount of time is what triggers it but I don't know exactly.
I should also point out that the car never has a problem starting (well now it will because I've posted this). You can actually listen to the car switch back and forth between sequential and batch mode when it thinks the sensor has failed.
So please anyone with an answer post a reply.
Let's start at the beginning. The drivetrain from this car is transplanted from the car that I wrecked back in 2003. So, the wiring harness in question throughout this ordeal came on the roller I purchased. Before this transplant I never had any issues with the cam sensor.
Without getting into every little detail of the story, I ended up with a code 41. I have since changed the cam sensor cap, the metripack connector for the cam sensor, the C3I module, and the harness connector for the C3I module. So I've been through 2 cam sensor caps, 2 ECMs, and 3 C3I modules. I've also made sure to get good metal to metal connection through the brackets that hold the C3I module to ensure a proper ground. Oh and I forgot to mention I ohmed out the wires that run from the cam sensor to the C3I connector and they check out OK.
So, I'm down to suspecting the wire that runs from the C3I to the ECM. I checked the ECM pin and the plug that goes into the ECM. Physically, they both look OK.
I need to find a way to check the wire itself or at least monitor that wire to see what the ECM is seeing. I was hoping someone would be able to tell me what I need to look for when I backprobe that pin. An old GM tech friend of mine said he wasn't sure but it's probably a 5v square wave that is being sent to the ECM.
So can someone tell me what to look for here? I doubt I can get access to an oscilloscope but it's not entirely out of the question. If I check it with voltmeter what should I see? What is the ECM looking for? Exactly what conditions have to be met for the ECM to trigger the code? I assume either voltage out of range or incorrect voltage to this pin over a certain amount of time is what triggers it but I don't know exactly.
I should also point out that the car never has a problem starting (well now it will because I've posted this). You can actually listen to the car switch back and forth between sequential and batch mode when it thinks the sensor has failed.
So please anyone with an answer post a reply.
