Intake Air Temperature Sensor Circuit Intermittent Low Voltage (GM)
What does P1112 mean?
The P1112 code means the vehicle's onboard diagnostic system has detected: Intake Air Temperature Sensor Circuit Intermittent Low Voltage (GM). This is a low severity code.
Common Symptoms
- Check Engine Light on
- Slightly lean running condition
- Minor idle roughness on cold starts
- Reduced fuel economy
- Occasional hesitation during acceleration
Probable Causes (Ranked by Likelihood)
- Defective intake air temperature (IAT) sensor Very High
- Short to ground in IAT sensor wiring High
- Water intrusion in IAT sensor connector Moderate
- Damaged wiring harness near IAT sensor Moderate
- PCM malfunction Low
Step-by-Step Diagnostic Procedure
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Check IAT sensor voltage with a scan tool at ambient temperature
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Inspect the IAT sensor connector for moisture, corrosion, or bent pins
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Measure IAT sensor resistance and compare to specifications
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Check for short to ground in the IAT signal wire
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Replace the IAT sensor if readings are out of specification
Frequently Asked Questions
What does P1112 mean?
P1112 on GM vehicles indicates the intake air temperature sensor is intermittently sending a lower-than-expected voltage to the PCM. This means the PCM thinks the incoming air is hotter than it actually is.
Can I drive with P1112?
Yes, you can drive normally with this code. The engine will compensate with default values. However, you may notice slightly reduced fuel economy and minor drivability issues.
How much does an IAT sensor cost?
A standalone IAT sensor costs $15 to $40. If it is integrated into the MAF sensor on your GM vehicle, the MAF assembly costs $50 to $150. Labor is typically minimal since the sensor is easy to access.