PCM short circuit?!
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From: Belgium
PCM short circuit?! I'm wiring my harness on the LQ4 and I have an issue with the PCM
Here is what I did:
PCM (blue connector) pin 1 to negative battery terminal
PCM (blue connector) pin 57 = C2 pin B8 (2 orange wires) receives the perm +12V
Once I put the blue connector into the PCM, my main fuse burns.
Am I doing something wrong?
Harness is from a Silverado 2006
Here is what I did:
PCM (blue connector) pin 1 to negative battery terminal
PCM (blue connector) pin 57 = C2 pin B8 (2 orange wires) receives the perm +12V
Once I put the blue connector into the PCM, my main fuse burns.
Am I doing something wrong?
Harness is from a Silverado 2006
Last edited by mjollnir; Aug 29, 2010 at 01:04 PM.
Thread Starter
On The Tree
Joined: Jan 2010
Posts: 177
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From: Belgium
I don't have a spare PCM (can't find that easily in Europe 
)
I just tested again, I only connected big red terminal to battery +, and the black wired terminal to battery -. Then I mesured voltage between pin B7 and B8 of connector C2 (underhood fuseblock), it reads 3.30V. I should have 12V there right?
Some more info: no short circuit between those 2 pins (reads 0.6V when harness power is unplugged) so I guess the PCM has a small battery to keep some settings like date/time when you change your main battery.
I don't know where the short comes from
)I just tested again, I only connected big red terminal to battery +, and the black wired terminal to battery -. Then I mesured voltage between pin B7 and B8 of connector C2 (underhood fuseblock), it reads 3.30V. I should have 12V there right?
Some more info: no short circuit between those 2 pins (reads 0.6V when harness power is unplugged) so I guess the PCM has a small battery to keep some settings like date/time when you change your main battery.
I don't know where the short comes from
Last edited by mjollnir; Aug 30, 2010 at 01:38 PM.
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On The Tree
Joined: Jan 2010
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From: Belgium
Thread Starter
On The Tree
Joined: Jan 2010
Posts: 177
Likes: 1
From: Belgium
The problem was evident when I opened the PCM:
A few shorts between some pins. Bad design there GM!!
The pins are easily pushed inside the PCM if the connectors are not perfectly aligned and parrallel to the PCM
Pins put back where they're supposed to be
Let's plug the OBD2 now
A few shorts between some pins. Bad design there GM!!
The pins are easily pushed inside the PCM if the connectors are not perfectly aligned and parrallel to the PCM
Pins put back where they're supposed to be
Let's plug the OBD2 now
