Fault code P011C – charge air temperature/intake air temperature correlation (Bank 1)

Fault code P011C is called “Charge Air Temperature (CAT)/Intake Air Temperature (IAT) Correlation (Bank 1)” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.

Technical description and explained code P011C

Stored code P011C means that the Powertrain Control Module (PCM) has detected a mismatch in the correlated signals. The mismatch is between the charge air temperature sensor (CAT) and the intake air temperature sensor (IAT) for Bank 1.

Fault code P011C – charge air temperature/intake air temperature correlation (Bank 1)

This code is only used in vehicles that are equipped with forced air devices and multiple air intake sources. The intake air source is usually the throttle valve. Forced-air devices include turbochargers and superchargers.

CAT sensors consist of a thermistor that protrudes from the housing on a wire stand. The resistor is positioned so that ambient air entering the engine intake can pass through it.

As the supercharger air temperature increases, the resistance level in the CAT resistor decreases, causing the circuit voltage to approach the reference maximum. The PCM sees these changes in the CAT sensor voltage as changes in charge air temperature.

The intake air temperature sensor (IAT) acts in much the same way as the CAT sensor. The IAT sensor is positioned so that the surrounding intake air passes through it as it enters the engine intake port. It is installed near the air filter housing or air intake.

Code P011C will be stored if the PCM detects voltage signals from the CAT sensor and IAT sensor that differ by more than the preprogrammed values. The Malfunction Indicator Light (MIL) may also illuminate.

It may take several failure cycles for the MIL lamp to illuminate.

Symptoms of vehicle malfunctions

The main signal that an error P011C has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

  1. Check engine control lamp on the control panel will light up (the code will be recorded in the memory as a malfunction).
  2. The engine stalls or starts badly (especially when starting cold).
  3. Floating revolutions, as well as attempts to stall at idle.
  4. Increased fuel consumption.
  5. Black smoke coming out of the exhaust pipe, if the mixture is rich.
  6. Increased NOx emissions may occur during lean mixture.

Error P011C is not a serious error, the car will be able to start and continue driving. But it is better to solve it as soon as possible, as it can affect fuel economy and engine performance.

Factors that can cause this error code

The error code P011C can mean that one or more of the following problems have occurred:

  • The charge air temperature sensor (CAT) has failed.
  • Intake air temperature sensor (IAT) is defective.
  • Open circuit in CAT or IAT sensor.
  • The wiring harness or connector for the CAT or IAT sensor is damaged.
  • Blown fuse.
  • Sometimes faulty PCM module is the cause.

How to fix or reset OBD-2 code P011C

Some suggested steps for troubleshooting and fix the error code P011C:

  1. Read all stored data and error codes with an OBD-II scan tool. To find out when and under what circumstances error P011C appeared.
  2. Clear the error codes from the computer memory and test-drive the vehicle to find out if error P011C appears again.
  3. Visually inspect electrical wiring and connections related to CAT and IAT sensors for looseness and damage. Repair the problem if necessary.
  4. If the CAT or IAT sensor has failed, replace it.
  5. Inspect the fuse; if it is blown, replace it.
  6. Clear the error code from the computer memory again, test drive the vehicle to see if the problem is resolved.

Diagnose and repair of problems

The first step in troubleshooting error P011C, is to review the Technical Service Bulletins (TSB). For known problems with a particular vehicle.

Perform a thorough visual inspection to check the wiring for obvious defects such as scratches, scuffs, exposed wires or burn spots. Next, check connectors and connections for safety, corrosion, and contact damage.

Be sure to carefully check the integrity of the wire harnesses and secure any loose wires. If you find a burned wire, solder it and make sure it is properly insulated.

Use a multimeter to test the charge air temperature (CAT) and intake air temperature (IAT) sensors. If you find a defective sensor, replace it.

On which vehicles does this problem occur most frequently

Fault code P011C can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:

  • Cadillac (Escalade)
  • Chevrolet (Equinox)
  • Dodge
  • Ford
  • GMC
  • GMC Terrain
  • Isuzu
  • Nissan
  • Toyota
  • Vauxhall

Fault code P011C can sometimes be found with other errors. The most common are the following: P011A, P011B, P011D.

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