Check Engine Light With Code P1870 on Cadillac Fleetwood

Problem Description and Possible Solution

The 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.

Problem Data
RepairPal Verified
Average mileage: (–)
1 model year affected: 1996
1 person reported this problem
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