PCM bricked??
05-28-2011, 09:22 AM
#1
PCM bricked?? The system: 15K 05 H2, 6.0 w/ all stock sensors, pcm, TAC, pedal. [Service # 12589463]. Was doing a WFO data log run, when at about 5500, there was a loud backfire, engine died, no restart, no starter turn. No FP prime. Scanner can't "detect" the vehicle. [I did manage to save the data log.]
WB and both NB sensor readings went whacko.
ETC will cycle as normal, when key is turned to on.
All other electrical items, such as lites, turn sigs, etc, work.
This a fresh/new everything install, in a 55 Chevy.
Back at the shop:
Checked all fuses..OK.
Checked at pin 20 and 57 on blu connector.. OK.
Harness is a Howell, w/ the 4 fuse inline panel.
Thot maybe the engine had "scrammed". Plugs ok, not locked up, no H2O in the oil.
Hooked the PCM to the bench harness>> Same error, "$0280 vehicle not detected", on the EFILIVE Flashscan.
I jumped the FP.. runs on jumper.
Jumped the Neutral relay. [It normally runs thru the PNP sw]. Engine turns over. [evidently, no 12v to PNP from pcm??]
2 Questions:
1. What should/could I be looking for, as the cause?
2. Is a failure such as this common/uncommon?
WB and both NB sensor readings went whacko.
ETC will cycle as normal, when key is turned to on.
All other electrical items, such as lites, turn sigs, etc, work.
This a fresh/new everything install, in a 55 Chevy.
Back at the shop:
Checked all fuses..OK.
Checked at pin 20 and 57 on blu connector.. OK.
Harness is a Howell, w/ the 4 fuse inline panel.
Thot maybe the engine had "scrammed". Plugs ok, not locked up, no H2O in the oil.
Hooked the PCM to the bench harness>> Same error, "$0280 vehicle not detected", on the EFILIVE Flashscan.
I jumped the FP.. runs on jumper.
Jumped the Neutral relay. [It normally runs thru the PNP sw]. Engine turns over. [evidently, no 12v to PNP from pcm??]
2 Questions:
1. What should/could I be looking for, as the cause?
2. Is a failure such as this common/uncommon?
11-23-2011, 09:05 AM
#3
Sorry bout that!! It seems I had a connector failure on the feed to the 4 fuse harness. [Howell harness w/ remote fuse panel.] The plug was shaking loose and causing the loss of power. [The plastic lock would not "hook' into place.]
No fault of the harness, a brain fart on my part!
11-23-2011, 10:22 AM
#4
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Glad it wasn't a major headache....
I neglected to post the "cure"...
It seems I had a connector failure on the feed to the 4 fuse harness. [Howell harness w/ remote fuse panel.] The plug was shaking loose and causing the loss of power. [The plastic lock would not "hook' into place.]
No fault of the harness, a brain fart on my part!
It seems I had a connector failure on the feed to the 4 fuse harness. [Howell harness w/ remote fuse panel.] The plug was shaking loose and causing the loss of power. [The plastic lock would not "hook' into place.]
No fault of the harness, a brain fart on my part!
