paxtonLT1

Hey guys hope I can get a little help. I'm working on a friends 94 camaro and went to tune it for him but I got no comunication with the pcm. Thought it was my laptop or cable but tested with a scaner at work and same thing. Even tryed a hyper tech programer that will turn on when you plug it into the obd port but then says no comuication, check cable. So I'm thinking its one of the wires from the port to the pcm guess I gota brake out the multimeter...................

moparman

Check the fuse. Think the port is on the same circuit as the cig lighter.

Injuneer

There is no 12V supply to the 12-pin OBD-I ALDL connector.

paxtonLT1

thats what i thought but i thought it was weird that the hypertech turns on when you plug it it poss triggered by ground? oh well now its time to start checking wires. thanks guys

paxtonLT1

ok so pin A is ground. pin B is diagnostic request. pin g is program imput, keyless entry receiver. and pin m is seral data line.key off I have ground on pins A,B,M and 7v on pin g.KOEO I have ground on pin A, 7 volt on pin G, and 4.9v on pins B and m. anyone know if thats all right? seems like it. Im not thinking a damaged wire anymore but a damaged pcm now.

paxtonLT1

ok so any reason i shouldn't swap the pcm from my 95 trans am into it. to see if i can get the scan tool to communicant with that?

paxtonLT1

ok so to anyone out there interested pcm was bad swaped in my pcm and whata you know it works. still runing like **** and has a code 24

Injuneer

If his 94 Camaro has the A4 trans, there will be a mismatch with the TC lockup signal from the the 95 PCM (on/off in the 94 vs. pulse width modulated in the 95).