P089C

What it means

P089C means the transmission control unit has seen the voltage on the second gear lever X position sensor circuit fall below the expected range. The X axis normally refers to one direction of movement of the gear selector, for example across the shift gate, though the exact layout depends on the vehicle. The control unit compares this signal with the first sensor, so a low reading can mean a fault in the sensor, its wiring or its supply.

Symptoms

• Gearbox warning light or engine management light on
• Gearbox stuck in one gear or in limp mode
• Gear selection feels wrong, is delayed or is refused
• Gear position shown incorrectly on the dashboard
• Engine will not start or the starter is inhibited in some positions
• Manual mode or paddle shift not working

Possible causes

• Short to earth or damaged wiring in the sensor 2 signal circuitlikely
• Faulty gear lever or selector position sensor (sensor 2 or the whole sensor assembly)likely
• Corroded, loose or water-damaged connector at the selector or control unitpossible
• Open circuit or high resistance in the sensor 5 volt supply or reference feedpossible
• Poor earth connection to the sensor or control unitpossible
• Internal fault in the transmission control unitrare
• Mechanical damage or contamination inside the gear selector assemblyrare

How to diagnose

1. Read all stored codes and freeze frame data, and note whether other selector, sensor supply or communication codes are present.
2. Check for any relevant technical service bulletins or known issues for the specific model and gearbox type.
3. Inspect the gear selector, its connector and the harness for damage, water ingress, corrosion, chafing or poor pin tension.
4. With a scan tool, view live data for both X position sensor signals while moving the selector, and compare sensor 1 with sensor 2.
5. Check the sensor supply voltage and earth at the connector against the manufacturer's wiring diagram.
6. Test the sensor 2 signal wire for a short to earth and for continuity back to the control unit with the battery disconnected and the connector unplugged.
7. Wiggle test the harness and connector while watching live data for dropouts or sudden low readings.
8. If wiring and supply are good, test or replace the selector sensor assembly, and only then suspect the control unit.

How to fix

• Repair or replace damaged wiring and fix any short to earth in the sensor 2 circuit.
• Clean, repair or replace corroded or loose connectors and terminals.
• Replace the gear lever or selector position sensor assembly if its signal is faulty, following the manufacturer's procedure.
• Restore the sensor supply or earth connection if it is open or has high resistance.
• Repair or replace the transmission control unit only after all other causes are ruled out, with any required coding or adaptation done to the manufacturer's procedure.
• Clear the code after repair and road test to confirm it does not return.

Can I keep driving?

Nearby codes

• P089BGenericGear Lever X Position Sensor 2 Circuit Range/Performance
• P089DGenericGear Lever X Position Sensor 2 Circuit High