1999 GMC Sonoma Q&A
1999 GMC Sonoma Question: engine light
check the cigarette lighter fuse,its integrated with your diagnostic link connecter.if its blown it wont communicate with a scan tool. - joelburke26
...d flushed radiator. Ran fine for a day then this. Checked vacuum lines and they are fine check engine light on as well.
A Loose or worn gas cap may cause Check Engine Light to illuminate.
...4 speed automatic transmission may develop a harsh 1-2 shift and/or illumination of the Check Engine Light with code P1870 stored. This can be caused by wear of the bore for the TCC isolator and reg...
The oxygen sensor can fail causing Check Engine Light illumination and the engine to run rich (...