Error code
OBD2 P0127
What it means
Intake Air Temperature Too High.
Severity
Summary
P0127 indicates that the intake air temperature sensor is reporting an abnormally high signal voltage to the PCM, which can be caused by issues with the wiring or the sensor itself.
Symptoms
- Stored trouble code and possibly an illuminated warning light
- Rough idling or fluctuating idle speed
- Engine hesitation, surging, or stalling upon acceleration when cold
- Increased fuel consumption
- Power loss
Common Causes
- Damaged, burnt, shorted, disconnected, or corroded wiring and/or connectors
- Defective IAT sensor
- Major air leaks near the IAT sensor location
- Defective MAF sensor (on some applications)
- Failed or failing PCM
Diagnosis
- Record all fault codes and freeze frame data.
- Locate the IAT sensor and inspect its connector and wiring for damage or corrosion.
- Perform electrical checks on the reference voltage, resistance, ground integrity, and continuity of the circuit.
- Heat the IAT sensor with a hair dryer while monitoring its output to check accuracy.
Fixes
- Replace damaged wiring or connectors as needed.
- Replace the defective IAT sensor if necessary.
FAQ
What does P0127 mean?
P0127 indicates an abnormally high signal voltage from the intake air temperature (IAT) sensor, which can be caused by issues with the wiring or the sensor itself.
How do I diagnose P0127?
Diagnose P0127 by inspecting and testing the IAT sensor's electrical circuit for damage or faults. Use a hair dryer to test the sensor’s accuracy while monitoring its output on a scanner.
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
More OBD2 codes
- P0100Mass or Volume Air Flow Circuit
- P0101Mass or Volume Air Flow Circuit Range/Performance
- P0102Mass or Volume Air Flow Circuit Low Input
- P0103Mass or Volume Air Flow Circuit High Input
- P0104Mass or Volume Air Flow Circuit Intermittent
- P0105Manifold Absolute Pressure/Barometric Pressure Circuit
- P0106Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance
- P0107Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
- P0108Manifold Absolute Pressure/Barometric Pressure Circuit High Input
- P0109Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent
- P0110Intake Air Temperature Sensor 1 Circuit
- P0111Intake Air Temperature Sensor 1 Circuit Range/Performance