Intake Air Temperature Circuit High Input Bank 1
The PCM detected that the Intake Air Temperature (IAT) sensor signal is reading higher than the expected maximum voltage range. This indicates either a sensor failure, wiring short to voltage, or a circuit problem that's causing incorrect air temperature readings to be sent to the engine computer.
What You Might Notice
- Check Engine Light (MIL) illuminated
- Possible rough idle or hesitation on acceleration
- Potential fuel mixture imbalance
- Slightly reduced fuel economy
- Engine may run in limp mode or safe mode
Most Common Causes
- 1
Failed IAT Sensor
The intake air temperature sensor has internally failed and is sending a constant high voltage signal to the PCM. This is the most common cause of P0113.
- 2
Short to Voltage in Wiring
The IAT sensor signal wire or reference circuit is shorted to positive voltage, causing the PCM to read an abnormally high value. This may occur due to damaged insulation or improper routing near high-voltage components.
- 3
Open or Loose Connection
A corroded, loose, or disconnected connector at the IAT sensor or in the signal circuit creates high resistance, which the PCM interprets as a high voltage condition.
- 4
Faulty PCM
Though less common, the PCM itself may have failed or developed an internal fault in the IAT signal processing circuit, causing false high readings.
How to Diagnose It
- 1
Check Failed IAT Sensor — The intake air temperature sensor has internally failed and is sending a constant high voltage signal to the PCM. This is the most common cause of P0113.
- 2
Check Short to Voltage in Wiring — The IAT sensor signal wire or reference circuit is shorted to positive voltage, causing the PCM to read an abnormally high value. This may occur due to damaged insulation or improper routing near high-voltage components.
- 3
Check Open or Loose Connection — A corroded, loose, or disconnected connector at the IAT sensor or in the signal circuit creates high resistance, which the PCM interprets as a high voltage condition.
- 4
Check Faulty PCM — Though less common, the PCM itself may have failed or developed an internal fault in the IAT signal processing circuit, causing false high readings.
How to Fix It
- 1
Replace IAT Sensor
Disconnect the IAT sensor connector, remove the sensor from the intake manifold or air intake tube, and install a new IAT sensor. Reconnect the electrical connector and clear the fault code to verify the repair.
- 2
Inspect and Repair Wiring
Visually inspect the IAT sensor harness and connectors for damage, corrosion, or signs of melting. Check routing near spark plug cables and alternator. Repair damaged insulation, reseat loose connections, or replace damaged wiring as needed.
- 3
Clean or Replace Connector
Disconnect the IAT sensor connector and inspect for corrosion or contamination. Clean with electrical contact cleaner or replace the connector if severely corroded. Ensure proper seating and a secure connection before reconnecting.
- 4
Test and Reprogram PCM
If other causes are ruled out, have a qualified technician test the PCM using factory diagnostic equipment. In rare cases, PCM reprogramming or replacement may be necessary, which typically requires dealer-level service.
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