Transmission problem?

[drob99]

Will a check engine light come on if there's a transmission code stored in the computer? I've been having rough shifting on my 02 GP GT with 91K.

[2000gpgtx]

See this post

http://www.automotiveforums.com/vbul...d.php?t=961154

[drob99]

Originally Posted by 2000gpgtx

See this post

http://www.automotiveforums.com/vbul...d.php?t=961154

that post has nothing to do with my problem. I dont have a transmission leak

[troy1]

You probably have a P1811 stored which will NOT turn on the SES light.

[2000gpgtx]

Fortunately, you haven't got the leak .. yet. But letting it go can lead to the leak from all the harsh shifts. The leak is more than likely the resulting damage of the problem described in that particular post which is the harsh shifting, the symptom you have described.

[BNaylor]

Originally Posted by drob99

that post has nothing to do with my problem. I dont have a transmission leak

Actually the thread does have a link posted that may help resolve or clarify your issue. See post #3 posted by tblake which will take you to a post at our Tips & Maintenance subforum.

Regardless of whether you have a SES/CEL light get it scanned and see if the infamous P1811 DTC is stored for retrieval as long as shift timing is off possibly caused by a line pressure (PCS) issue. The harsh/hard shifting normally upshifts is caused due to maximum line pressure being commanded by the PCM module as a result of the P1811 DTC setting. All you need is a odb-ii scanner capable of reading out GM manufacturer extended codes. P1XXX.