TCC only works when cold
 

Hello all.

I'm about to take off on a long trip and would like to achieve the highest mpg I can. Lately, my TCC on works when the engine/tranny are cold. Once warm and after making a stop, the TCC will disengage and remain that way until the car completely cools.

I was wondering if there is a quick fix to this problem. I read once that a deffective temperature sensor somewhere may to blame.

What do you think?

Thanks!
Larry S.

'94 SSEi

Are you getting a "Check Engine" light at all?

Is your fuel pump loud? It could be a fuel pump. Same problem on the Trans Sport and it was the fuel pump. Also pressure was perfecly fine at idle. . . .so check when you are having the problem. . . . .

Yeah, I think there is a TCC engage inhibit until the engine comes up to normal op temperature. Input from the ECT sensor is what is the controlling factor. The transmission also has a temp sensor internal. The 92-99 guys will chime in here soon.

Codes on the car need to be checked... We also need to know what the PCM is seeing...

the 94-95 PCM's act in a diffrent manner,

If you are at the right speed, even with a cold engine, say you crank the car and a minute later you are on the highway, by the time you get to 60-70 the TCC will be commanded on due to roadspeed...

Once up to temp you should have the TCC activate at 36-40 mph in Drive, and 46-50 in OverDrive....

Chances are you will not get the SES light, but you may have a stored code... Again you need to know what the PCM is seeing from all of the sensors that relater to the TCC and what its trying to do.... ;)

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The SES light DOES come on intermittently. I had an Autozone attempt to pull the codes but a connection to the ECM couldn't be made so no codes were retrieved. This is an ODB I system, right?

I don't notice the fuel pump being any louder than normal.

Thanks for the help so far.

--Larry S.

no you have the OBD 1 1/2 and I have had problems with Advance reading the OBD 1 1/2

Me too. It's due to the fact that it is NOT an OBDII system. The actron scanner's they use are OBD II only. They even say on their sign somewhere that if you have a 96 and newer car we can scan your car. I don't know what the manufacturers were thinking during the OBD I to OBD II transistion period. There are tons of cars out there within the 93-95 range that have OBD II connectors with an OBD I system. :roll: I mean come on, either change the system entirely or don't do it all. This "hybrid" between the two is nothing by a pain in the arse.

Does anyone have any tips for retrieving stored codes from the so called ODB 1 1/2 systems?

Has anyone used WinALDL (http://winaldl.joby.se/) ???

Thank you,
Larry S.

I'll have to Tech info an explanation when I find the time...

Yes the 94-95 H and C bodies with the 3800's are OBD1 compliant, but they use an OBD2 connector and OBD2 codes...

The problem is that everyone looks at the connector on a GM and if its not an ALDL they think its a full on OBD2 system because it had the 16 pin OBD2 connector...

But what you need to scan this car and or cars is a scantool that will read 94-95 GM cars with an OBD2 connector... Most OBD1 scantools like the Actron 9110 will read these cars with the 16 pin OBD2 connector...

I also have an actron that will read all 84-95 GM's with either connector...

Keepp in mind that in 95 there were a few models that already supported the OBD2 system...

This can get a bit confusing, but these 94-95 Bonneville can be scanned with an OBD1 scantool capeable of reading GM cars with the aid of the OBD 2 connector...

Good Luck ;)

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