Crank/no start. Getting 12v at pin P of the ICM connector(drops to 10v during crank) but I dont get a spark on any wires. Engine was working perfectly before the swap. ICM harness checked out as good. ICM grounded through the harness and the back plate(is that needed?). ECM has not thrown any codes.
Is this a new swap? Did you buy or build your harness? Was you PCM reprogreammed? Are all your fuses good? Do you get a Check engine light during bulb test when you turn the key on? Do you have power to the PCM at pins C1-19 and 20 with the key on?
Is this a new swap? Did you buy or build your harness? Was you PCM reprogreammed? Are all your fuses good? Do you get a Check engine light during bulb test when you turn the key on? Do you have power to the PCM at pins C1-19 and 20 with the key on?
Yes, build, yes(Sinister), yes, yes, didnt check. How would the ECM make a connection to an OBD2 sensor if 19/20 didnt have power?
Crank sensor was going to be my next suggestion to if everything else checked out. But if you tested it and it was good, i cant imagine it just failing.
Crank sensor was going to be my next suggestion to if everything else checked out. But if you tested it and it was good, i cant imagine it just failing.
Yeah engine was running fine right before swap (really well actually). Thinking about it, I accidentally swapped battery connectors (neg for pos) without the computer plugged in. Could that have fried the icm?
I suppose its possible, but I doubt it. I have done that a couple times without damaging anything. You can usually take your ICM to the parts store for free testing.
I suppose its possible, but I doubt it. I have done that a couple times without damaging anything. You can usually take your ICM to the parts store for free testing.
Both O'Reillys and Autozone said they dont do it..
If it was running fine before i would go through double checking all the basics before replacing the ICM, make sure your engine and chassis is grounded well along with what i listed earlier.
If it was running fine before i would go through double checking all the basics before replacing the ICM, make sure your engine and chassis is grounded well along with what i listed earlier.
Thats what I spent the last few days doing. Every wire is connected correctly, the car has a 4ga ground from the battery and two 4ga straps from the engine to the body, and every sensor is properly grounded. The ICM harness is also solid. The fuel pump runs, the car cranks, and the ECM doesnt throw any codes and connects to the OBD2 sensor. All fuses have been properly replaced and have not blown. I have vacuum to the fuel pressure regulator and EVAP. The only thing I have NOT checked is the +12v for the computer, injectors, and other misc sensors.
At this point it almost HAS to be the ICM(and it is grounded). Considering I have +12v to it and its not working. The volts drop to 10 during crank, is that normal?
A working crank sensor and a good ICM will produce a spark while cranking the engine over even without the PCM connected to the harness.
If the ignition key was on and ICM was wired up and connected to the harness when you hooked the battery up backwards, then yes, you could have fried it.
A bad ignition module, bad crank sensor, and/or bad related wiring could all cause a no spark condition. But that's about all that could cause it.
------------------ OVERKILL IS UNDERRATED Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com
A working crank sensor and a good ICM will produce a spark while cranking the engine over even without the PCM connected to the harness.
If the ignition key was on and ICM was wired up and connected to the harness when you hooked the battery up backwards, then yes, you could have fried it.
A bad ignition module, bad crank sensor, and/or bad related wiring could all cause a no spark condition. But that's about all that could cause it.
Yeah, at this point it is either the crank sensor or the ICM. The wiring is one wire from the E3 of C500 to the ICM harness + good grounds, and since that wire is getting +12v...I hope to god it is not the crank sensor..
