Car Problem Reports

GMC Jimmy Check Engine Light With Code P1870

GMC Jimmy Problem
14 Reports
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Model Years Affected: 1996, 1997, 1998, 1999, 2000

Drive Trains Affected: 4WD, Automatic Transmission

Average Mileage: 182,920 mi (96,000 mi - 242,000 mi)


Vehicles equipped whit a 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 regulator valves in the valve body. This condition does not commonly occur until the transmission reaches normal operating temperature. If the valve body is worn, replacement will be necessary to correct this concern.

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