This code indicates the transmission control module is detecting abnormally low voltage in the position sensor circuit for shift fork D, which is used in certain automated manual or dual-clutch transmissions to track the physical position of that shift fork. A 'circuit low' condition typically means the signal wire is shorted to ground, the sensor has failed internally, or the reference voltage supply to the sensor is missing. The controller uses this position data to coordinate gear engagement, so an unreliable signal can prevent proper shifts.
The position sensor itself can fail internally, producing a short-to-ground condition on the signal line. This is the most common root cause for a circuit-low code on this circuit.
Chafed insulation, rodent damage, or a pinched harness can short the signal wire to ground or interrupt the reference voltage feed, causing the controller to see near-zero volts.
Poor contact at the sensor or TCM connector—especially from moisture intrusion or terminal spread—can drop voltage low enough to trigger a circuit-low code.
If the shift fork or its actuator is mechanically stuck or binding, the sensor may report a position outside the expected range. This is less common for a pure circuit-low code but can contribute if the sensor is mechanically damaged.
A failure inside the transmission control module's input circuitry is possible but rare. It should only be considered after the sensor, wiring, and connectors have been fully verified.
No. The transmission may fail to engage gears correctly or enter limp mode, which can leave you stranded and potentially cause internal transmission damage if shifting is forced.
Usually not. The far more likely cause is the shift fork D position sensor itself or a wiring/connector fault. Replacing the control module without fully testing the sensor and circuit is a common and expensive misdiagnosis.
You can clear it to see if it resets immediately, but if the fault is present the code will typically return on the next drive cycle. Continued driving with an active shift-fork position fault is not recommended.
Not necessarily. Many P2842 cases are resolved by replacing a position sensor or repairing a wiring fault without internal transmission work. A proper diagnosis is needed before assuming major mechanical failure.