Hey all,

After reading the many pages of excellent advice on this forum and trying to correct the problems myself, I'm still having some issues.

I have a 98 vert that won't shift (automatic trans) automatically. I have to start the car off in first gear and shift manually. It seems to be running a little rough as well. I have a check engine light on and a service vehicle soon error message. I get the following current codes:

P0705
P0713
P0740
P0748
P0758
P0785
P1810
C1281

I have cleaned the following grounds although none appeared to be corroded:

G201
G103
G101
G102
G104
G202

I drilled new holes into the frame and installed self-tapping screws to for the grounds located on the frame rails G101, G102, G103 & G104 just to make sure it has a good contact. After purchasing the car, I noticed it had some acid damage on the plastic connectors around the battery. I cleaned all of the connections here as well but none seems to have any corrosion. I even removed the rear panel behind the passenger tire to access the grounding block and inspect the TCM. No corrosion anywhere?

Can anyone help me? What am I missing? At my wits end.

 

how long have you had the car?

Did it just start doing this out-of-the-blue... or were you experiencing minor problems beforehand?

Have you had any service performed, or any new mods added ?

 

http://www.corvettedoctor.com/Code_Main.html When you get to your year,Scroll down and click "read more"...............Paul

 

Thanks for the replies. History before this problem, I'll try to be brief. Bought the car with salvage title 3 years ago. Car had been repaired. Badly. (all I could afford) I noticed an acid leak around battery, wires corroded at plastic connectors but no wires seemed to be damaged. Month after i got it, got the service engine soon, check engine, reduced engine power, service traction control, etc. Took to dealer, they replaced EBCM. Messages went away, for 6 months. Same messages came back, took back to dealer. They said I needed TCM & Steering Sensor control? I told them after reading this forum to look for a bad connection, bad ground, loose wire, etc. before I bought more expensive electrical components. After 3 weeks and 3 different technicians working on car, they called me and said they found a broken wire. They wanted my permission to spend up to $1500 to fix it but even then they weren't sure if it was going to correct the problem. I said I'd come get the car. They called me back 5 minutes later and said that now my car won't shift. I asked what happened. He said me must of knocked a wire loose somewhere. I said fix it. He said they can't and to come get it. I called the service manager. He said he didn't want to fix the car and to come get it.
So, I took the advie of the forum and proceeding to look for bad connections, etc. I cleaned 9 of the 13 ground so far. None corroded. I cleaned the connections at the TCM and the splice pack underneath. No corrosion, no fixes. I cleared the codes and read the current one left and they refer to trans but I don't know what to do about them. I don't know where to go from here. Extremely leary of being taken for a ride again, I can't afford it. HELP!!!! please

 

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Have you checked the connections at both ends of the wiring between the PCM and the Auto-trans ?? The codes listed indicate to me that the PCM is having difficulty communicating with the auto-trans ... the codes cover problems with the trans temp sensor, torque converter solenoid, etc.

I'm guessing that the connection at the PCM has had battery acid contaminate and degrade the connections.

Good luck,

HTH

 

thanks for the reply. Do you know if that connection is at the battery area or if it's near the trans?

 

The wiring comes from the underside of the transmission and snakes to the engine compartment. Under the battery is where it comes out, and then connects to the wiring to the PCM. I'd check there first (under the battery) , it is a 20 wire bundle connecting with round GREY connectors (many of the other connectors are rectangular) in that nest of cables under the battery. I'd suspect that either it is corroded, or maybe a wire or the connector came loose due to the stealership techs playing around in there.

You might qalso send a PM to Bill Curlee as he is the electrical guru on here and see if he has any recommendations.

 

Thanks a bunch!!!!