P11C9 Possible Causes
- Faulty Intake Air Temperature (IAT) sensor
- Intake Air Temperature (IAT) sensor harness is open or shorted
- Intake Air Temperature (IAT) sensor electrical circuit poor connection
How do I fix code P11C9
Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
Cost of diagnosing the P11C9 code
Labor: 1.0The cost of diagnosing the P11C9 code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
P11C9 Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P11C9 MeaningThe Intake Air Temperature (IAT) sensor is variable temperature sensitive resistor that measures the temperature of the air in the intake system. Sensor resistance will change based on air temperature. The higher the temperature is, the lower the resistance. The Engine Control Module (ECM) provides a reference voltage and monitors the voltage drop between a fixed value internal resistance and the sensor resistance. This is called a voltage divider circuit.
IAT sensor values are used by the ECM processor to assist with the calculation of idle speed, fuel mixture and spark advance.
Inaccurate voltages from the IAT sensor may affect pulse-width, idle quality, and tail pipe emissions. Intermittent signals may cause hesitation, stumble and surging. If an IAT sensor failure accompanies an Engine Coolant Temperature (ECT) sensor failure, cooling fan operation may also be affected.
Some manufacturers incorporate the Intake Air Temperature (IAT) sensor as part of the Mass Air Flow (MAF) sensor (Air Flow Meter).
P11C9 More InformationNeed more information on how to fix the P11C9 code?
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