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Hello all,
I've been perusing forums trying to find a solution to my problems for a weeks, but haven't quite found the exact solution to my problem, so here goes the whole story. (I'll try and condense as much as possible)
This all started about 2 years ago when the Colorado spun a rod bearing. I hadn't been around , and this truck was sort of the family spare vehicle, so my brother pulled the engine out, put a new crank in and rebuilt the bottom end. Some time went by and I finally put the motor back in and hooked everything back up, but when I went to start it, I had the main power and the switch line shorted on the starter, so as soon as you would push the clutch in (M/T) the starter would engage, regardless of if the key was on or not.
So, I fixed my shorted wire situation, but the starter would still engage with the clutch pushed in when the key was in the on position. We thought we must've fried the lock switch mechanism, so we replaced that, problem continued. Our cheap little code reader wouldn't read anything, so we let it sit for a while because we didn't have time to mess with it.
A few weeks ago, My brother and I decided to tear back into it and do some more troubleshooting. I have access to a Snap-On Modis scanner so I borrowed that, and I couldn't get it to communicate with the vehicle at all, I keep getting a Class 2 Serial Communication error. Thought maybe the body control module was junk because when we pulled the kick panel out, the control module was wet, so I got a used one from ebay, but I'm having the same problems.
Now, I'm thinking it's the engine control module (ECM/PCM) but I don't want to order parts and have the same issues that I'm having now.
-All fuses are good
-No OBDII communication
-Fuel Pump will only run when bypassing the relay
-Starter will only engage when bypassing the relay (Starter no longer engages when clutch is pushed in)
-Problem persists with both body control modules
-Passlock light is on
Is there any way to test the PCM at a component level? If the PCM functions properly, then I know that I have a wiring problem somewhere.
TL;DR - Can't communicate with OBDII, think the PCM is junk but don't know how to test it.
I should also note that I took a multimeter and probed some of the wires going to the PCM, and I measured 5V from the PCM ground to vehicle ground, which I didn't think I should see. Not sure if that means anything to anyone.
Thanks!
I've been perusing forums trying to find a solution to my problems for a weeks, but haven't quite found the exact solution to my problem, so here goes the whole story. (I'll try and condense as much as possible)
This all started about 2 years ago when the Colorado spun a rod bearing. I hadn't been around , and this truck was sort of the family spare vehicle, so my brother pulled the engine out, put a new crank in and rebuilt the bottom end. Some time went by and I finally put the motor back in and hooked everything back up, but when I went to start it, I had the main power and the switch line shorted on the starter, so as soon as you would push the clutch in (M/T) the starter would engage, regardless of if the key was on or not.
So, I fixed my shorted wire situation, but the starter would still engage with the clutch pushed in when the key was in the on position. We thought we must've fried the lock switch mechanism, so we replaced that, problem continued. Our cheap little code reader wouldn't read anything, so we let it sit for a while because we didn't have time to mess with it.
A few weeks ago, My brother and I decided to tear back into it and do some more troubleshooting. I have access to a Snap-On Modis scanner so I borrowed that, and I couldn't get it to communicate with the vehicle at all, I keep getting a Class 2 Serial Communication error. Thought maybe the body control module was junk because when we pulled the kick panel out, the control module was wet, so I got a used one from ebay, but I'm having the same problems.
Now, I'm thinking it's the engine control module (ECM/PCM) but I don't want to order parts and have the same issues that I'm having now.
-All fuses are good
-No OBDII communication
-Fuel Pump will only run when bypassing the relay
-Starter will only engage when bypassing the relay (Starter no longer engages when clutch is pushed in)
-Problem persists with both body control modules
-Passlock light is on
Is there any way to test the PCM at a component level? If the PCM functions properly, then I know that I have a wiring problem somewhere.
TL;DR - Can't communicate with OBDII, think the PCM is junk but don't know how to test it.
I should also note that I took a multimeter and probed some of the wires going to the PCM, and I measured 5V from the PCM ground to vehicle ground, which I didn't think I should see. Not sure if that means anything to anyone.
Thanks!
