P1829: Transmission Transfer Case Counter Clockwise Shift Relay Coil Open Circuit

P1829 is a powertrain code that logs when the control module detects an open circuit in the coil of the relay responsible for driving the transfer case motor in the counter clockwise direction. On electronically controlled transfer cases, electric motors or actuators are used to shift between 4WD modes, and relays control the direction of motor rotation. An open circuit in the counter clockwise relay coil means the module can't energise that relay, which will prevent the transfer case from completing shifts that require counter clockwise motor rotation.

An open circuit fault like this typically comes down to a failed relay, a broken wire in the relay coil supply or control circuit, or a poor connection at the relay socket or module connector. Start by checking the relay itself, as these are inexpensive and easy to test or swap. If the relay is fine, check the wiring between the control module and the relay coil terminals for continuity and inspect connectors for corrosion or spread terminals.

Severity is medium. Depending on which transfer case mode the vehicle was in when the fault occurred, you may find the transfer case is stuck in a particular range. Prolonged use with a failed shift relay can put stress on the actuator trying to complete incomplete shifts. It's worth sorting relatively soon, particularly if you depend on being able to move between 2WD and 4WD modes reliably.