What it means
The charge air cooler temperature sensor circuit signal for Bank 2 is intermittent or erratic.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The Bank 2 charge air cooler temperature sensor measures the temperature of compressed air after that bank's cooler. P00A4 sets when its signal changes erratically or cuts in and out, often because vibration or movement interrupts contact in the sensor connector or wiring.
Common causes
Most likely first.
- Connector loose or corroded
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Check engine light on
- Intermittent loss of power or boost
- Poor fuel economy
How to diagnose it
- Review freeze-frame data and live Bank 2 temperature readings for sudden jumps or dropouts, noting when they occur.
- Inspect the Bank 2 sensor connector for looseness or corrosion and check whether the harness rubs against a vibrating or moving component.
- With live data displayed, gently move the Bank 2 connector and accessible harness sections to see whether the reading changes, following safe service practices.
- Check the Bank 2 signal, reference, and ground circuits for intermittent continuity or poor terminal contact using the manufacturer's procedure.
- If the wiring remains stable, test the Bank 2 sensor for intermittent output and verify the module connection.
Common fixes
- Secure the Bank 2 connector and harness to prevent vibration-related movement.
- Clean or replace loose or corroded connector terminals.
- Repair chafed or internally damaged Bank 2 sensor wiring.
- Replace a Bank 2 sensor that produces intermittent readings after its circuit is verified.
Can I keep driving?
Limit driving to gentle trips if the engine remains stable, since boost or power may drop unexpectedly when the Bank 2 signal cuts out. Avoid fast traffic, towing, and hard acceleration until the intermittent fault is repaired.
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.