I have a 1995 SL2 with 168,000 & automatic transmission. The car starts off in high gear(high rpms, takes a long time to come up to highway speed). When up to speed runs fine but will not down shift manually & the check engine light has come on. Filter & fluid have been changed. Thanks

 

VALVE body?Edited by: sw2cam

 

^^that would be my guess as well

 

What are the SES codes?

 

How to display codes

What they meanEdited by: Low Saturn

 

I''d also check the TSS (turbine shaft speed) sensor. It''s located on the front of the transmission near the filter. Also check the VSS (vehicle speed sensor) located on the rear of the transmission by the axle shaft. Those two sensor will also cause shifting problems.

 

The car will also tell you what''s wrong if you check to see why the SES light is on.

 

Thanks for the responses. Got to checking electrical connections out at the main buss under the hood. But what I did notice isthat when this shifting problem happened...these items stopped working, dome light, door locks & radio(sometimes not on). Checked the buss connections at the console, found loose connection from (red) power at back of buss. Changed connector, ok. Don''t know if it was time for loose connection or not, but that''s what it was.

 

Hopefully that tunes out to be it. Kinda nice when its something simple.