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.
Check Engine Light With Code P1870 on Chevrolet Express 3500
Average mileage: 98,000 (98,000–98,000)
6 people reported this problem
1 person shared problem details
1998 Chevrolet Express 350098,000Visitor
Hard 1st and 2nd shift. Starts after the van has been driven for awhile. When van is turned off sand restarted problem is gone.
One or both secondary air injection check valves may become restricted causing poor air flow re...
While traveling at freeway speed, the check engine light came on. The next time I came to a sto...
My van has a check engine code of p1345 ignition control and also a secondary emission control...
I have a Chev 98 3500 Extended van. I have no leaking fluid, I changed the thermostate today a...
A Loose or worn gas cap may cause Check Engine Light to illuminate.