98 Saturn Transmission Problem

saturn
sl

#1

I have a 98 Saturn SL1, 100K miles, automatic. For the past year, I’ve been having a problem with the transmission (I think). It happens only when the car is hot and only in specific situations. When I’m driving on the highway at high speeds (65+ mph) and have to slow down really suddenly (e.g. for construction), the car refuses to shift properly… the engine reeves up to 3K+ rpms and will not go above 30 mph. If I pull over and allow the engine to cool, it is fine again. Also, sometimes after this happens the car with jerk when going into reverse. Any feedback on what might be wrong would be very appreciated!!!


#2

Has the Check Engine Light come ‘on’? If so have the PCM scanned for codes. Post these back for our input. Is the OD light constantly ‘on’ or flashing when this happens? If so have the PCM scanned while the problem is present i.e. do not shut the engine ‘off’ until the codes are read.

Hopefully something will appear that will steer you and us in the right direction.


#3

Hi. Thanks for your help! Yes, the Service Engine Soon light comes on. Last time I had it read when this happened it said something concerning the gear ratios. I didn’t get the exact code, though. I haven’t noticed the OD light coming on. Hope that helps. I’m afraid I need a new transmission but am hoping there might be a less expensive fix! Thanks again!


#4

I am not that conversant with the adaptive strategy of the Saturn PCM software. But, if a gear ratio DTC code has appeared that indicates that one of the transmission clutches could be slipping. It could also be the torque converter lockup clutch slipping. Any slipping clutch will heat up the oil. The PCM will adapt by forcing the line pressure to the highest level and shift the transmission into ‘limp home’ mode. This strategy will be maintained until the engine is turned ‘off’ and the transmission oil cools.

If you are feeling lucky, you might run this by a qualified transmission technician who can read the stored codes, review the freeze frame data, check the line pressure, and give you a diagnosis. I suspect that you are right that the transmission will have to be rebuilt.

Hope this helps.