P0705 Fault Code in Audi: Causes, Symptoms, and Fixes

P0705** indicates that the Transmission Range Sensor (TRS) — also known as the Neutral Safety Switch — is sending incorrect or no data to the Engine Control Module (ECM) or Transmission Control Module (TCM) about the current gear selection (P, R, N, D, etc.).

Common Symptoms:

1.️ Check Engine Light (CEL)
2. Car won’t start or only starts in Neutral
3. Gear position indicator on dash is blank or wrong
4. Reverse lights not working
5.️ Harsh or delayed shifting
6. Transmission stuck in limp mode

Common Causes:

1. Faulty transmission range sensor (TRS)
2. Misaligned sensor or shift linkage
3. Damaged wiring or corroded connector
4. Faulty TCM or ECM (rare)
5. Water intrusion in the connector (common in DSG gearboxes)

How to Fix It:

✅ Step-by-step:
1. Scan transmission module
– Look for gear mismatch or signal dropout from TRS
2. Check wiring & connectors
– Look for broken, corroded, or loose TRS connectors
3. Inspect sensor alignment
– Sensor must be aligned with actual shifter position (e.g., PRNDL must match)
4. Replace the TRS if faulty
– Often mounted on the transmission housing near the shift linkage
5. Clear the code and retest

Common in:

1. Audi/VW DSG (DQ250, DQ200)
2. BMW (ZF 6HP/8HP)
3. Mercedes-Benz (722.9)
4. Hyundai, Honda, Ford, Toyota, etc.