Automatic Transmission Gear Indicator Problems of Chrysler Pacifica

Safety complaint regarding a severe can bus communication failure in the 2017 Chrysler Pacifica (gas model, base trim, no engine stop-start) resulting in a sudden loss of transmission control while driving. The defect manifests as an intermittent loss of communication between the electronic shifter module (esm) and the transmission control module (tcm). Without warning, the rotary shifter (prndl) indicator lights go dark and a "service shifter" message appears. This triggers a cascade of safety system failures, disabling electronic stability control, forward collision warning, and blind spot alerts. Most critically, the loss of network data causes the vehicle to enter "limp mode," locking the transmission in its current gear and refusing to upshift or downshift, creating a severe crash hazard in active traffic. The root cause is a physical hardware defect in the can-c star connector junction block (part no. 68321746aa) located behind the passenger-side glovebox. The pin receptacles inside this distribution block degrade and lose tension, allowing data wires to vibrate loose. Striking the passenger-side dashboard physically reseats the pins, instantly restoring network communication, shifter lights, and transmission function. Dealerships are misdiagnosing this defect by following factory diagnostic trees that mandate replacing the functional electronic shifter module (an ineffective $1,400 repair) instead of addressing the faulty star connector. My vehicle has been at the Chrysler dealership since initial diagnosis with no resolution, as the dealer refuses to repair the known wiring defect without first replacing the functional shifter. The sudden loss of transmission control and active safety systems due to this faulty communication block is an extreme safety hazard. Chrysler must issue a mandatory recall to replace these degraded star connectors.

See all problems of the 2017 Chrysler Pacifica 🔎.

Vehicle was in reverse (r), changed to drive (d) in "prndl" selector and vehicle moved backwards instead of forward when accelerating causing a collision. Police incident report was filled, and Chrysler corporation contacted. Vehicle is at Chrysler dealership for transmission malfunction investigation.

See all problems of the 2018 Chrysler Pacifica 🔎.