New Engine Install - Rough start then Stalls

[roaniecowpony]

Oops.

I pulled out for a test drive and got a CEL. Codes show a loss of PCM com, no fan, etc. again. This is with the original PCM that the shop unlocked the security lock. But they evidently didn't do a full diagnostic like I asked. Called them. They said ship it back and they'll clone it onto a spare PCM I have or they'll use one of theirs. It's on the way to them.

Taking it to the dealer for programming would be a hassle if I had to tow it in so they could program through the OBD port.

Sponsored

 

[SadRobot]

Oops.

I pulled out for a test drive and got a CEL. Codes show a loss of PCM com, no fan, etc. again. This is with the original PCM that the shop unlocked the security lock. But they evidently didn't do a full diagnostic like I asked. Called them. They said ship it back and they'll clone it onto a spare PCM I have or they'll use one of theirs. It's on the way to them.

Taking it to the dealer for programming would be a hassle if I had to tow it in so they could program through the OBD port.

Ah so close!

 

[roaniecowpony]

Well, I did get progress. I have more of it back together. I'll put the skids on this week and maybe install the diff skids I have still in the box. I really want to get it going for a Rubicon trip in a month.

 

[SadRobot]

Well, I did get progress. I have more of it back together. I'll put the skids on this week and maybe install the diff skids I have still in the box. I really want to get it going for a Rubicon trip in a month.

I hope you get it going in time. I wish I could do the Rubicon this year but looks like it'll have to be next year.

 

[Rangemaster]

Crank and throttle relearns done, fenders and grill installed, and recharging AC.

Finally, F-yea. Reminds me of my 87 Square Body step side restro.

 

[frondel]

Oops.

I pulled out for a test drive and got a CEL. Codes show a loss of PCM com, no fan, etc. again. This is with the original PCM that the shop unlocked the security lock. But they evidently didn't do a full diagnostic like I asked. Called them. They said ship it back and they'll clone it onto a spare PCM I have or they'll use one of theirs. It's on the way to them.

Taking it to the dealer for programming would be a hassle if I had to tow it in so they could program through the OBD port.

Hey were you ever able to figure it out? I'm facing the same exact thing right now, except I've got my PCM reprogrammed. No crank, clicking from the ASD relay. I'm 99% sure it isn't my harness. What did it end up being for you?

 

[roaniecowpony]

Hey were you ever able to figure it out? I'm facing the same exact thing right now, except I've got my PCM reprogrammed. No crank, clicking from the ASD relay. I'm 99% sure it isn't my harness. What did it end up being for you?

The PCM was dying and eventually went to total no-start of the new engine. I sent my PCM to Wrangler Fix and it went back and forth twice, then a third hand "unlocked' PCM to Wrangler Fix and found it didn't work. Then bought a brand new Mopar PCM and sent it to them. Took twice for that one to come back where it would work.

 

[frondel]

The PCM was dying and eventually went to total no-start of the new engine. I sent my PCM to Wrangler Fix and it went back and forth twice, then a third hand "unlocked' PCM to Wrangler Fix and found it didn't work. Then bought a brand new Mopar PCM and sent it to them. Took twice for that one to come back where it would work.

Wow, so nothing short of a new PCM fixed it? And with the new PCM and a following unlock you've been good since then? And to confirm, nothing was also wrong with your harness?

 

[roaniecowpony]

Wow, so nothing short of a new PCM fixed it? And with the new PCM and a following unlock you've been good since then? And to confirm, nothing was also wrong with your harness?

Nothing wrong with the harness. The PCM was dying. The fan control section of the PCM failed and it overheated the engine, killing it. The other sections of the PCM failed later. Guessing it was moisture intrusion.

 

[roaniecowpony]

No "unlock" of the new PCM that I'm aware of. My understanding is that a new PCM needs to be programmed with the VIN to communicate with the other modules on the vehicle (Body computer, etc.)

Sponsored