P0705

What the Code Means

P0705 is a Transmission Range Sensor Circuit Malfunction. The code means the control unit (DME/EGS) isn't getting a reliable signal for the current selector position.

The transmission range sensor (also called the position sensor) reports the selected mode to the control unit: P, R, N, D, or manual mode. The control unit uses that data to set shift logic, allow engine start (only in P or N), and control the reverse lights.

Possible causes:

• an open or damaged wire in the sensor circuit;
• a faulty transmission range sensor;
• a problem with the transmission control unit (EGS) or its software.

Symptoms

• Engine start problems (the starter doesn't engage or the engine won't start).
• You can't shift gears.
• The transmission drops into limp mode (limited gears, stuck in one gear).

Diagnosis and Repair

1. Read the fault codes with diagnostic equipment (ISTA, INPA) to confirm P0705 and check for related errors.
2. Check the transmission range sensor and its electrical connectors.
3. Check the wiring in the sensor circuit for opens, shorts, and corroded contacts.
4. If the sensor tests bad, replace the sensor.
5. After the repair, clear the codes and take a test drive to confirm the transmission shifts correctly.