Technical Description of OBD-II Trouble Code
Correlation Between Charge Air Temperature and Intake Air Temperature in Bank 2
What does that signify?
This generic powertrain diagnostic trouble code (DTC) is applicable to all OBD-II vehicles, including Nissan, Toyota, Chevrolet, GMC, Ford, Dodge, Vauxhall, and others. The specific repair steps may vary depending on the make and model.
A stored code P011D indicates that the powertrain control module (PCM) has detected a discrepancy in the signals between the charge air temperature (CAT) sensor and the intake air temperature (IAT) sensor for engine bank number two.
Bank 2 refers to the engine bank that does not contain the number one cylinder. This code is used in vehicles equipped with forced air induction devices and multiple intake air inlet sources, such as turbochargers and superchargers.
CAT sensors consist of a thermal resistor that protrudes from the housing on a wire pedestal. The resistor is positioned to allow ambient air entering the engine intake, after leaving the intercooler, to flow across it. As charge air temperature increases, the resistance in the CAT resistor decreases, causing circuit voltage to move towards the reference maximum. The PCM interprets these voltage variations as changes in charge air temperature.
The CAT sensor/s provides data to the PCM for boost pressure solenoid operation, boost pressure release valve operation, fuel delivery, and ignition timing calculation.
The IAT sensor functions similarly to the CAT sensor and is positioned to allow ambient intake air to pass across it as it enters the engine intake. The IAT sensor is usually located near the air filter housing or air inlet pipe.
A code P011D will be stored and a malfunction indicator lamp (MIL) may illuminate if the PCM detects voltage signals from the CAT sensor and the IAT sensor that differ by more than a preprogrammed degree. Multiple ignition cycles with a failure may be required for MIL illumination.
What is the severity of this DTC?
The conditions contributing to a stored code P011D can adversely affect overall engine performance and fuel efficiency, making it a severe issue.
What are some of the symptoms of the code?
Symptoms of a P011D trouble code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some P011D diagnostic steps?
Before attempting to diagnose a code P011D, it is recommended to have access to a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable vehicle information source.
Start diagnosing any CAT sensor related code by ensuring there are no obstructions in air flow across the intercooler.
If there are no intercooler obstructions and the air filter is relatively clean, visually inspect all CAT/IAT system wiring and connectors. Make necessary repairs as required.
Next, connect the scanner to the vehicle diagnostic port and retrieve all stored codes and freeze frame data. Freeze frame data provides a snapshot of the exact circumstances at the time of the malfunction that led to the stored code P011D. It is helpful to write down this information for the diagnosis process.
Clear the codes and test-drive the vehicle to see if the code is reset.
If the code is reset:
If the sensors comply with the manufacturer’s specifications:
If reference voltage and a ground are present:
If the sensor signal circuit reflects the correct voltage:
If all CAT/IAT sensors and circuits are within specifications, suspect PCM failure or a PCM programming error.
