I am just going by what I was told by the tech who looked at the car. But I have no way to verify it. So that is where I need help

Well..I have the 95 GM FSM in front of me. It says nothing at all about the trans on 1670. 1670 is only the AC relay, low speed fan relay and high speed fan relay. My assumption would be that if you swapped out those three relays or found one of them to be bad, that the code would go away and you'll be left with a transmission issue.

Sorry.

Searching....hmmm this might help some? Ignore the first part about fixing the Quad codes, but read after...

Yeah the mechanic is telling me all the components on that circuit are not listed you have to look in an expanded database to find them. Can you tell me what pins WD 10-13 feed off the PCM? I will try and get by and get the sheet he has that lists all the components on that circuit.

I will also check that fuse. Would be awesome if thats all it was

Extended database? That'* new.

So I am going to get that list of all the other things the mechanic says is on that circuit tomorrow hopefully. But reading thru some older post I found another instance of bogging down and an error code p1670.

https://www.gmforum.com/showthread.p...ighlight=p1670

Admittedly we don't know everything.. however I have access to GM'* online FSM'* and the actual paper books. None are mentioning something in that area, neither is my post from back when that you linked. Fully ready to help you out though. Let'* look at it from 15 different ways and see if we can't solve it. What is pins WD 10-13? The PCM has three connectors, each with pins 1-16. EDIT: WD I think stands for White connector, column D

On connector 2 aka the one I think is white, pins D10-D13 are the trans.
D10 Dk Blue circuit 473
D11 Dk Grn Circuit 335
D12 Dk Grn/Wht Circuit 459
D13 Brn/Wht Circuit 419

Going back to the P1670 page It shows D10 as High speed cooling relay
D11 Low speed cooling relay
D12 AC Relay
D13 Malfuction indicator light aka SES Ign fuse 1 15 amp.

Further..you mentioned the AC working. Page 3 of the code states that if the AC is on all the time or off all the time that it'* likely that relay. Here'* the scrub.. they want a Tech 1 tool to do stuff and we don't have one.

Here'* a test.. Unplug the three relays for P1670 and see if the trans still acts up. Be careful though because w/o the fan relays your fans won't come on at all and you'll be cooled only by airflow. Fan'* don't normally come on until 216F low speed and 228F for high speed. So you should be ok for a test drive.

The FSM also mentions that you could have a bad relay or something else grounding the circuit. Doesn't really say what though. So you'll kinda be testing things and I think from your ac mention that it'* the ac or it'* relay. If that doesn't work the FSM does suggest a new pcm.

So it does have to do with the transmission then? I will test it by taking out the relays and get back with what I find. I wont be able to test it till Friday.

If it is the PCM then what is my best bet to getting a replacement? What are we looking at on cost?

Thanks again for the time spent trying to help me.

Try local salvage yards. Ebay might have them. Also try local parts stores.

Sorry..that quote you nabbed was part of something I had typed up before I found what the WD probably means.

The pins listed are for exactly what I listed them as.. AC and fans. there'* no reference to trans. Code 1650 is all about the trans and the trans soleniods and TCC. 1670 though...no dice..

Maybe there'* a shared ground etc..but we won't know for sure until you are able to do testing.

A JY by me charges about $20 for a pcm. Advance charges $80-$120.