PCM bent pin 26

[ioamnesia]

Howdy. I'm in the 2nd cirle here so please help me out. After changing the oil on my 98 explorer I removed the harness from the PCM to get the shield off for voltage testing (dreaded p0171 and p0174) and plugged it back in. In the process, pin 26 was bent over. The car was running rough on my test drive after working on the car and broke down about a block away. Crank, no start. I pulled the PCM out and noted the bent pin which, as far as I can tell from the scematics, goes to the ignition coil. I carefully unbent the pin and replugged in everything, making sure not to have a repeat performance. No Start!

I checked the fuel rail and have zero pressure. Relay is good. I bridged the relay to start the fuel pump and got pressure to the engine. I then tried to have someone start the car as I shorted the relay ports and still no joy.

I don't know... did I fry the PCM? I probed the wire and the lead to the relay and the relay is not getting voltage from the PCM when the key is turned on. Is it possible somehow the whole chip in key system was wonked out somehow and the pcm is not recognizing my key?

 

[Willard]

does the CEL come on when you try and start it? if no then you might have fried it.

 

[Turdle]

here is a fuse location chart-there are several PCM and PCM relay fuses-

http://www.explorerforum.com/forums/showthread.php?t=180814&highlight=power+layout


BTW, I deleted your other thread--
maybe you forgot you had started it?

welcome to the forum--

 

[ioamnesia]

I'll double check all fuses when I get home but I think I ran the gamut the other day. Any other ideas?

 

[ioamnesia]

Yippee, it was the PCM power diode fuse! But now the engine is running really rough and CEL'ing after one start.... Time to go to Autozone to get the CEL codes. At least she drives... sorta

 

[Turdle]

phew--
Please post up what you find--

 

[ioamnesia]

Seems that pin 26 going to the ignition coil was a good sign of where to look, I drove to autozone and got a CEL pointing to the coil. Pulled it out and it was cracked and leaking replaced and it's running great.... EXCEPT

P0171 and 174 are BACK. DAMNIT.

I've replaced plenum gaskets (even though it's not SOHC), O2 sensors, TPS, MAF, and BUBKISS. No vacuum leaks detectable. Any help?

 

[budwich]

I would reset everything both with a scanner and the battery cable "stuff" (disconnect) so that system relearns everything. If you had coil problems, the system might have been compensating for that among other things. Give it some "run time" as per operating "normally" and see if things are ok.

 

[ioamnesia]

I would reset everything both with a scanner and the battery cable "stuff" (disconnect) so that system relearns everything. If you had coil problems, the system might have been compensating for that among other things. Give it some "run time" as per operating "normally" and see if things are ok.

No good, if you had looked up above, the error codes were around before the coil problem which was caused by my dinging around with the computer. I've cleared the codes god knows how many times. Also checked fuel pressure and that looks good too.

 

[budwich]

from your post, I thought the bent pin was on the pcm connector.... which is a problem "after the fact". However, I further thought that you then noticed that the coil was cracked while you were "playing around with said pin" from a code scan. But what I think is that you don't know when the coil was first cracked and could have been "degraded" for a long time. Hence, my suggestion of initializing everything... code scan only clears CEL, it doesn't clear "run memory" which contain the "operating settings" that the system has "learned" during its operation including trying to accommodate "broken things" like maybe a "faulty coil". Anyways ... good luck.

 

[4x4xbrian.com]

Have you cleaned the MAF? buildup causes lean mixture.
cheap to try.

 

[snoranger]

Have you cleaned the MAF? buildup causes lean mixture.
cheap to try.

I really hope he solved this problem already. Its been 5 years.