View Full Version : 94 Deville will stay in second gear after "service engine soon" light comes on


NeedClue
09-28-04, 01:25 AM
Hello folks, this is my first post and I just bought my first Cadillac last month. I know nothing about car maintenance, but would like to share this problem and get some advice.

One night I was driving around 55mph when the "service engine soon" light came on and rpm immediately increased. After turning the vehicle off and back on the light would reset, however the problem would come back at around 45mph. Next day the light was back at 32mph and it would not shift away from what sounded to be second gear. I think the brakes are also being applied whenever this light comes on, but very slightly, enough to keep me from picking up speed too fast when I press the gas pedal.

Took it to a transmission shop and they ran it on a computer, told me it wasn't a transmission problem, and gave me fault codes 47 (BCM to PCM serial data problem) and 102 (shorted brake booster sensor).

Took it to another place specialized in electrical maintenance and they came up with fault codes P039 (torque converter clutch), P094 (vehicle speed sensor), A040 (door air mix valve circuit), T072 (serial data link fault), and S061 (right front position sensor). They told me to take it to the dealer.

I haven't been to the dealer yet and don't know if it will be the right choise to make. However, I can't possibly imagine the cost to fix all these problems. Anyone have any ideas or advices concerning this problem?

jimbo1972
06-08-05, 01:07 PM
Did you ever find the problem with this?? My buddy is haveing the same problem.
thanks

caddydaddy
06-08-05, 03:00 PM
If the speed sensor is bad, it will hold a gear. The torque convertor clutch will increase the engine RPM's at highway speeds, but won't effect the driveability like the speed sensor does.

Dennisk
06-08-05, 07:00 PM
Sounds like the transmission solenoid problem, The shift solenoids A and B wear out and cause this type of problem. Do a search on the forum for transmission solenoids or have a look at this thread.

http://www.cadillacforums.com/forums/showthread.php?t=36344&highlight=transmission+Solenoids

:rolleyes2