OBD-II code · Powertrain (generic)
P01AC Alternative Fuel Tank Temperature Sensor Circuit Low
Alt fuel tank temp sensor signal voltage below expected range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with P01AC?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- Parts involved
- Alt Fuel Tank Temp Sensor, Sensor Wiring
Related codes
- P01A9Alternative Fuel Rail/System Pressure - Too High
- P01AAAlternative Fuel Tank Temperature Sensor Circuit
- P01ABAlternative Fuel Tank Temperature Sensor Range/Performance
- P01ADAlternative Fuel Tank Temperature Sensor Circuit High
- P01AEAlternative Fuel Tank Temperature Sensor Circuit Intermittent/Erratic
- P01AFAlternative Fuel Tank A Level Sensor Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.