'91 4L80e Harness/Controller Question [Archive]

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GSXMEN

01-11-2006, 21:03

I just bought a freshly rebuilt tranny out of a '91 small schoolbus. I also got the TCM from it.....still have to get a harness.

From what I understand, the diesel's had a 'stand-alone' harness. The one in this bus appears to integrate with the 6.2/6.5 engine(not sure which engine that one had).

I bought this with the idea of using it in a carb'd gas application.

Any idea if the harness that's in this bus will work to control the tranny? Or do I need to get a harness elsewhere?

Appreciate any help - Thanks!!

01-12-2006, 16:59

It had to be the 6.2 if it was still the factory engine. I'd ask this question in the 6.2 forum. It'll be noticed more

GSXMEN

01-12-2006, 17:25

That appears to be a 'member's only' section.....at least that's what I got when I first tried to go in there.

How would one go about getting a password for that section? (other than a donation)

Here's hoping it gets noticed here.

GSXMEN

01-12-2006, 17:27

Also, if any of you guys would happen to have a wiring schematic for the early('91) 4L80e - that should also be beneficial!! :cool:

More Power

01-13-2006, 12:08

The 91 wiring harness connects to an engine speed sensor and throttle position sensor on the diesel engine. You can obtain similar components for a gas engine installation. GM installed the 4L80-E behind the gas 454 in that same model year.

The ECM programming will likely be less than ideal for a gas engine due to the rpm range differences between a gas & diesel engine. www.jetchip.com (http://www.jetchip.com) could help provide a replacement program chip for your ECM that would be more suitable for a gas engine.

Jim

GSXMEN

01-14-2006, 07:12

Thanks Jim!!

Regarding the tach output sensor wiring, do you know if a normal tach could be spliced into that wiring connector? Or would I need something special?

I managed to find a wiring schematic and pinout chart for a 93&newer 4L80e....however, I understand there are slight differences from those to the earlier trannies. Maybe the basics are the same, but the connectors themselves are different??

According to that, I seem to need a + and -, TPS, VSS & TOSS. Would that seem to be it, or is there anything else?

I've also found several places to install a TPS onto any carb. So, that part of it should be no problem.

The diesel's TCM that I pulled out of it carries Serv. No. 16147609 with the code AWRS after it. Does that sound correct for a '91 unit?

Thanks again guys!! :cool: