Theory Of Operation

WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The Transmission Control Relay is used to supply power to the solenoids and pressure switches when the transmission is in normal operating mode. The relay output is fed back to the TCM through pins 26, 27 and 28 in the C1 harness connector. It is referred to as "Transmission Control Output". This circuit does not supply power to the TCM, it is only a sense circuit. When the relay is off, no power is supplied to the solenoids or pressure switches and the transmission is in "limp-in" or "default" mode. Note: Inadequate Transmission Control Relay Output voltage can cause DTCs P0846, P0869, P0871, P0876 or P0988 to set. This does not indicate an internal transmission or solenoid/TRS problem. Repairing the P0882 fault should eliminate the related DTCs.