Questions and Answers

Chevy Lumina DTC P1870 Q. Hi Vincent, I have a 1996 Chevy Lumina. The service engine soon light will not go off, and the P1870 code keeps coming up. I am having trouble finding what this code means. Do you have any idea? Thanks, Jonathan

A. This code means that the PCM is seeing a slip condition inside the transmission. What this means is you need to monitor the TCC at cruising speed to see if it's coming on. This code means that there is slippage somewhere. It could be a valve in valve body hanging up, bad clutch pack, TCC inoperative, lot's of things could be the cause.

My suggestion is to see a dealer and maybe there is a new software update or a service bulletin that covers this code for a possible easy fix and not an overhaul.