What it means
The charge air cooler coolant temperature sensor A reading is outside the expected range or does not behave as expected. This code does not refer to the engine coolant temperature sensor.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
In a water-cooled charge air cooler, sensor A measures the temperature of coolant serving the cooler that removes heat from compressed intake air. The control module sets P00DF when sensor A's reading is outside its expected range or fails to respond as expected; this concerns the charge air cooler circuit, not the engine coolant temperature sensor.
Common causes
Most likely first.
- Sensor reading drifted
- Sensor element aged beyond calibration window
- Sensor mounting loose - signal damping
Symptoms
- Check-engine light on
- Reduced engine performance or power
- Poor fuel economy
How to diagnose it
- Review freeze-frame data and live sensor A readings, comparing them with engine coolant and ambient readings to see whether the charge air cooler temperature is plausible.
- Inspect sensor A's mounting and connector for looseness, contamination, or damage that could disrupt heat transfer or electrical contact.
- Observe live data as the engine warms and operating conditions change to check whether sensor A responds smoothly.
- Check the wiring and sensor output against the manufacturer's specification to separate a drifting sensor from a circuit problem.
- If the reading remains implausible with a sound sensor circuit, inspect charge air cooler coolant flow and heat management.
Common fixes
- Secure sensor A in its correct mounting position.
- Repair damaged wiring or connector contacts in the sensor A circuit.
- Replace sensor A if its reading fails the manufacturer's range or response test.
- Repair a charge air cooler coolant flow problem if one is found.
Can I keep driving?
Avoid sustained heavy acceleration if power is reduced, because unreliable cooler-temperature data may cause poor boost control or reduced engine performance. Stop if the engine overheats or severe power loss occurs; this sensor is for charge air cooler coolant, not engine coolant.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.