P011C–P011D Charge Air Cooler Temperature/Intake Air Temperature Correlation Bank 1
Two sensors that should agree with each other do not, so the ECU cannot tell which one to trust.
Can you drive it? The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
P011C | Charge Air Cooler Temperature/Intake Air Temperature Correlation Bank 1 | Investigate soon |
P011D | Charge Air Cooler Temperature/Intake Air Temperature Correlation Bank 2 | Investigate soon |
The definition
P011C: Charge Air Cooler Temperature/Intake Air Temperature Correlation Bank 1.
P011C is a powertrain code (the engine or gearbox), defined by the SAE standard - it means the same thing on any make of car, and any generic OBD-II reader will decode it.
What to check first
Cheapest and fastest checks first:
- Read the freeze-frame data stored with the fault - engine speed, load and temperature at the moment it logged tell you whether this happens cold, hot or under load.
- Check the connector at the part for corrosion, and that it is fully seated.
- Clear the code and see whether it returns, and under what conditions.
What actually causes this on a VAG
Two temperature sensors are being cross-checked against each other: the one after the intercooler and the intake air temperature sensor. This code says they disagree by more than the control unit allows. The check is typically evaluated after the car has stood long enough for everything under the bonnet to settle, when both should be reading the same thing - namely the outside air temperature. So this does not mean the intercooler has failed. It means one of the two readings is wrong, and the code cannot tell you which.
Most likely causes, in order
- One sensor drifted or fouled with oil. An oil film from the crankcase breather over the sensor tip makes it read slowly and inaccurately, which is exactly what a correlation check catches. The cold-soak comparison in the note below tells you which of the two is lying.
- Connector or wiring fault at one sensor. Corrosion, a spread terminal or a damaged strand shifts a reading enough to fail the comparison without causing an outright circuit fault. Unplug both sensors, check the pins are clean and tight, and reseat them before replacing anything.
- Aftermarket intercooler, charge pipes or intake. If a sensor has been relocated into different airflow, or left sitting in a pipe that is not where the control unit expects it, the correlation check can fail with nothing actually broken. Check what has been changed on the car and whether both sensors are in their intended positions.
- Charge cooling not working as expected. Less common for this particular code, but on engines with a water-cooled charge cooler, an auxiliary coolant pump that has stopped or a low level in that separate low-temperature circuit leaves the post-cooler temperature far higher than it should be. That pump runs on demand rather than whenever the ignition is on, so check it with a scan tool's output test, or by feeling the hoses after a hard run, and check the level in the charge-cooler expansion bottle - it is separate from the engine's own.
Worth knowing: This is one you can narrow down yourself in a couple of minutes with no parts at all. Leave the car overnight, switch the ignition on without starting the engine, and read both temperatures on a scan tool alongside the outside air temperature. They should all sit within a degree or two of each other; the one that does not is the faulty sensor. Replacing both sensors on spec is a common and completely avoidable expense. And if they do agree on a stone-cold car, do not simply clear the code and hope - the fault is then more likely to be in a connector, or in the charge cooling itself, than in either sensor.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads every module in a VW, Audi, Skoda or SEAT — not just the engine — shows the live measuring blocks behind this fault, gives you the freeze-frame conditions it was logged under, and clears it once you have fixed it. It also does what a generic OBD reader cannot on a VAG: service resets, coding, adaptations, and Stage 1–3 flashing with your original file saved first.
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Common questions
What does P011C mean?
P011C means Charge Air Cooler Temperature/Intake Air Temperature Correlation Bank 1. Two sensors that should agree with each other do not, so the ECU cannot tell which one to trust.
Can I drive with P011C?
The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.