Problem with overdrive
Car shifts ok with no flares or bumps. Driving down highway it will not go into overdrive…rpms stay at 3k @70mph. No faults stored. Trans oil level ok. has new transmission oil pan installed previously…dont know why. Any input would be appreciated!
Is it commanding a shift of you watch on scanner? Are temperature sensors (ect and tft) reading accurately?
You usually can watch the commands as JJ stated.. And, if the temperature is too low in the trans module, it will not allow the shift. If it's commanding the shift, but the shift isn't happening, it'll usually flag a code for ratio errors. Since yours does not, there is something going on with the command side I believe.
Test drove vehicle found vehicle speed sensor data under transmission control module reading 30 mph while vehicle is actually at 60 MPH. The VSS data from the PCM and abs module and OBD2 are all okay, however the right front wheel speed sensor is inoperative. After much driving finally Set code c1203 in abs module…strange…could this all be caused by faulty wss? Will look further into it later…
updating this, almost ordering a new TCm/valve body. No codes…tcm data shows mph negatively correlating with actual mph…when doing 60mph, tcm says 30mph…revolution sensor inside tcm is my suspect. Anyone else care to chime in?
Do you have a separate PID for VSS Meter? Also, out of curiosity, was the wheel speed sensor issue ever addressed?
The wheel bearing was replaced, that solved the wheel speed issue but no change in transmission behavior. pcm data shows correct mph, instrument cluster data shows correct mph, abs data shows correct mph….only tcm data showing corrupt mph…service data says when revolution sensor in transmission is faulty, trans will default to shift only up to fourth gear. strange thing is, its not setting a…