94 Bonneville Overdrive / Cruise Control inop

[schnitzel]

I just finished replacing the throttle position sensor on my car when the SES light started comming on. The light was not there before I replaced the sensor and has been on since the first start afterward. In addition, the car will no longer shift into OD and the cruise control doesn't work. I tried putting the old TPS back on but nothing changed so maybe the TPS is just a coincidence. I also disconnected the battery to see if that would help but it didn't. Everything else with the car is fine - starts OK, accelerates great, does not miss or stall, still gets good gas mileage. There are no loose connections, connectors, hoses that I can find. I didn't take any off except for the TPS connector. The TPS connector is a bit "crumbly" but the contacts are good.

The SES light is constantly on.

Any suggestions?

[LMP]

Is it back to normal now?
Well, just in case: Try to read positively the voltage on connector B as you move throttle from idle to full throttle (key ON but engine not running). SHould read from .5 to 4.5 V. see diagam www.avigex.ca/xport/dtc22.jpg
Retreive code to see if it is related - probably is, . (connect A to B on diagnostic plug and read SES flashes). If code 21 or 22 stored, it will not allow 4th gear, cruise or torque converter clutch operation.
If the code has been set accidentally (like turning the key ON while TPS was disconnected) then possibly it requires several normal operation cycles before clearing itself out.

[randman1]

Getting the car scanned for codes would narrow things down quite a bit. Try going to Autozone. They will usually scan the car for free.

That being said, my guess is that you will at least have a code 38 (TCC brake circuit). The ECM has a +12v input from the TCC brake (actually part of the switch for the brake pedal). This input "sees" +12v unless the brake is pressed (kinda opposite of the wat the brake lights work) If the ECM does not see proper operation of this circuit, TCC lock-up will not occur. Also the ECM has a circuit from the brake pedal that controls the cruise control. I don't know exactly how the whole circuit works though.

You might just have a fuse problem preventing voltage from going to that brake switch.

[schnitzel]

Problem fixed. Took it to a shop to have it checked and they determined that the TPS was installed incorrectly. OD and cruise are back again with no more problems. Last time I try to change a sensor in the freezing rain!

Thanks for the help guys. Until next time...

[LMP]

Good.