No start electrical issue need help please(long post)
Tech Contributor
Joined: Dec 1999
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Theres NO TDR in the BCM.. Theres a DRIVER (basicaly a transistor) that allows the signal to go to ground..
YES... it can be bad but,,,,,,,,,, if it were me,,,, i would follow that pin thru the circuit board and see if theres any issues along that path. if you dont find anything wrong,,, dont panic yet.
Make SURE that all the POWER and GROUNDS are proper and working..
BC
YES... it can be bad but,,,,,,,,,, if it were me,,,, i would follow that pin thru the circuit board and see if theres any issues along that path. if you dont find anything wrong,,, dont panic yet.
Make SURE that all the POWER and GROUNDS are proper and working..
BC
Last edited by Bill Curlee; Apr 27, 2012 at 06:22 PM.
Thread Starter
Racer
Joined: Aug 2010
Posts: 280
Likes: 0
From: Tyler Texas
I took the BCM out and look over it closely earlier today. I did not see any corrosion or and resisters that were swaild up. There were also no broken or burn spots along any of the paths.
Drifting
Joined: May 2010
Posts: 1,482
Likes: 2
From: Pearland, TX
Drifting
Joined: May 2010
Posts: 1,482
Likes: 2
From: Pearland, TX
If you can live without the ignition's anti-theft stuff, you could just ground the black/yellow wire. That doesn't explain the fuel cutoff though. Do you have a way to see if the fuel pump is still running when the engine dies? I know I can hear mine, but mine isn't stock.
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Thread Starter
Racer
Joined: Aug 2010
Posts: 280
Likes: 0
From: Tyler Texas
correct me if I am wrong but the yellow/black wire from the TDR goes to the BCM and controls the starter enable relay control. By grounding the yellow/black wire I am bypassing the BCM. I read in another post were the fuel cut off from the TDR is also connected to the BCM. Here is part of the post I am looking at....
The body control module (BCM) produces the theft deterrent crank relay and fuel enable signal when ignition is ON and the proper ignition code voltage value is detected. The powertrain control module (PCM) monitors the fuel enable signal during crank. If the proper signal is present on the Class 2 Serial Data Circuit, the PCM enables the fuel delivery in order to allow the engine to start. If the PCM determines that the fuel enable signal is not present or incorrect while the engine is running, DTC P1626 is set. The engine continues to start and run as long as DTC P1626 is stored. If the problem affects inputs to the VTD signal, the starter motor may be disabled.
Conditions for Running the DTC
The body control module (BCM) produces the theft deterrent crank relay and fuel enable signal when ignition is ON and the proper ignition code voltage value is detected. The powertrain control module (PCM) monitors the fuel enable signal during crank. If the proper signal is present on the Class 2 Serial Data Circuit, the PCM enables the fuel delivery in order to allow the engine to start. If the PCM determines that the fuel enable signal is not present or incorrect while the engine is running, DTC P1626 is set. The engine continues to start and run as long as DTC P1626 is stored. If the problem affects inputs to the VTD signal, the starter motor may be disabled.
Conditions for Running the DTC
Thread Starter
Racer
Joined: Aug 2010
Posts: 280
Likes: 0
From: Tyler Texas
LOL I am cursed........Not only is the vette having issue, my truck I commute in (at the dealership) is also having weird electrical issue with a plug under the dash.... NOW my damn company vehicle is giving me reduced engine reading.....Maybe I omit an electrical charge that is killing everything.
What a week....I guess it will get better, at least until my wife's truck dies.
If I don't figure the vette out by next week Ill take it to East Texas Muscle Car in Longview. I hear good things about them, and there closer than Houston.
What a week....I guess it will get better, at least until my wife's truck dies.
If I don't figure the vette out by next week Ill take it to East Texas Muscle Car in Longview. I hear good things about them, and there closer than Houston.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Well,,,,,,,,, I keep reading all this stuff over and over again,, trying to come up with a smoking gun.
It sure sounds like you missing something. Your were in the ignition switch so,, I Recommend that you measure the Hot in run and start voltages for the BCM and PCM.
The normal start during crank but DIE in ON tells me,,, You have an issue with the 12VDC out of the ignition switch when the switch is in the ON position.
Look in the IGNITION SWITCH REPAIR POST. It has all the hot in ON and start fuses that need to be tested for proper ignition voltages. Unless your getting full battery voltages on each terminal in that ignition switch, it wont run correctly.
Lothar34 You are correct,, that may be a relay control instead of a driver.
The fuelpump has the driver control for the relay.
BC
It sure sounds like you missing something. Your were in the ignition switch so,, I Recommend that you measure the Hot in run and start voltages for the BCM and PCM.
The normal start during crank but DIE in ON tells me,,, You have an issue with the 12VDC out of the ignition switch when the switch is in the ON position.
Look in the IGNITION SWITCH REPAIR POST. It has all the hot in ON and start fuses that need to be tested for proper ignition voltages. Unless your getting full battery voltages on each terminal in that ignition switch, it wont run correctly.
Lothar34 You are correct,, that may be a relay control instead of a driver.
The fuelpump has the driver control for the relay.BC
Thread Starter
Racer
Joined: Aug 2010
Posts: 280
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From: Tyler Texas
Hey Bill I checked voltage on all the fuses and I had a credit at oriely's so I used it to get a new ignition switch but I am still in the same spot. I agree with you I am missing something but I keep checking things over and over. I am going to try and do a PCM - BCM relearn for giggles.
Last edited by larryu; Apr 27, 2012 at 07:40 PM. Reason: Miss info
Thread Starter
Racer
Joined: Aug 2010
Posts: 280
Likes: 0
From: Tyler Texas
I think I am at my ends with it. I think I am going to take it to East Texas Muscle Car in Longview and let them look at it. I work to much and don't have as much time as I use to. With a new house and still needing to unpack its just a lot to take on. I'll post any findings.
Drifting
Joined: May 2010
Posts: 1,482
Likes: 2
From: Pearland, TX
Oh come on, it's just one more thing to try. ETMC is a speed shop, they may not be in any particular hurry to diagnose your electrical problems if you're not buying a supercharger or something.
Thread Starter
Racer
Joined: Aug 2010
Posts: 280
Likes: 0
From: Tyler Texas
ok well the mechanic said he found a bad ground wire inside one of the looms. It was one that was responsible for the Fuel pump relay and O2's and a third circuit I don't remember which one. So I will pick it up tonight after work and keep my fingers crossed.
