Katmandu

I should clarify that this truck is an EARLY 98 (Made 11/07) 12 valver. I'm sure the PCMs are different. Should "probably" be the same as a 97 then I assume.[/quote]

I have NO power on PIN #12 key-ON. Is this correct then ?

Is this the ESS (Engine Speed Sensor) near the damper ? Or the one located at the back of the engine ???

infidel

There is no sensor (CPS) at the back on the engine, that's a 24 valve thing.

'94&'95 are the only years that have the same PCM, all the other 12 valve years are different.

vzdude

97 or early 98 , either way, if it affecting all the guages, it's a pcm or ccd bus issue.

Katmandu

Where's a good place to find a used PCM ?

Do I look for a 97 (since it's a 12 Valver and built 11/1997) or go with a 98 ?

vzdude

Best thing to do is to get the number off of your old one to match it up. MANY different options. Try car-part.com too. The website will automatically sort by closest parts.

Katmandu

1998
05014155AA
56040139AA
56040139AB

From this website....

http://www.aa1car.com/library/2004/c...ailability.pdf

I still need to do the final check on that CPS. It's gonna have to wait a bit. I work 3rd Shift and have been up A LOOOONG time.

vzdude

You need the number off of YOUR pcm. Should be a label. Even if the pcm has been flashed ( which changes the number ) ( look for a label either on the core support or the pcm itself), if you get me those numbers , I can give you a list of all pcms that will work. And a price on a new one too!

Need95-00CTD

first things first, pull apart the plugs on your PCM, find the light green wire with a black stripe and check to make sure you have voltage, if you don't, either your fuse is blown, a wire is cut, or shorted out somewhere. Thats what happened with my problem, find the short, find your problem.

To test the PCM I just spliced into the green and black wire that runs into the PCM, cut it, and spliced it right to the cigarette lighter (only thing I knew had power with the ignition on). When I got back my gauges I knew the PCM wasn't dead.

vzdude

I would agree.....that is still a possibility. Double check that first. There are NUMEROUS splices in that wire too! You did double check fuse 4 & 9 too right?

Katmandu

Yes. Both are GOOD.

Katmandu

Which plug and position is it on ???

Need95-00CTD

I don't recall. IIRC its the plug closest to the drivers side, and the 5th from the left on the bottom, but it doesn't take long to pull the back cover off of it and trace the right wire to the right pin. Make sure you check the pin itself, not the wire running into it, as infidel often states the connectors in these things are prone to cracking pins or losing them all together.

Katmandu

Ok, I've got a PCM (used) coming in the mail.

A local mechanic here says I "may" need to have the Dealership REFLASH it to make it work.

It's my understanding that 12 Valvers don't need the PCM to run.

Do I really need to get the PCM reflashed from the Dealership or is this unnecessary ?????

vzdude

As long as it is a used one, it may run with some lights and such ( check engine ect, ect,) . The dealer may have to reprogram the VIN for things like abs and such, but the basic functions should still work ( like charging and all!)

Katmandu

It's the exact same # 56040139AC. I'm hoping it's plug and play.

It should be here tomorrow.