P00A4
Charge Air Cooler Temperature Sensor Circuit Intermittent/Erratic Bank 2
Forced induction / air temperature
Generic OBD-II
Low
What it means
P00A4 means the computer is seeing an intermittent or erratic signal from the bank 2 charge-air-cooler (intercooler) temperature sensor, which measures the temperature of the compressed air after the intercooler. It usually points to a loose connector or chafed wiring rather than a failed sensor, and rarely affects how the car drives.
Low
Can I keep driving? Usually fine to drive — this is an intermittent sensor-signal fault; on a turbo/diesel the ECM may occasionally limit boost until it's fixed.
Common symptoms
What you'll notice
- Check-engine light on, sometimes coming and going
- Occasional stored code with no obvious driving change
- Possible brief loss of boost or reduced power on turbo/diesel engines
Common causes
Most likely first
- Loose, backed-out, or corroded connector at the charge-air-cooler (intercooler) temperature sensor on bank 2Likely
- Chafed or intermittently broken wiring in the sensor circuitCommon
- Failing charge-air-cooler temperature sensor with an erratic outputCommon
- Moisture or oil contamination in the sensor connectorLess often
- Rarely, an ECM/PCM faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to see when the fault sets (cold, hot, over bumps).
- Locate the bank 2 charge-air-cooler (intercooler outlet) temperature sensor and inspect its connector for corrosion, spread pins, or looseness.
- Wiggle-test the harness and connector with the engine running to reproduce the intermittent signal.
- Check the sensor wiring for continuity and shorts against a known-good bank 1 reading.
- Replace the temperature sensor if the wiring and connector are good and the signal is still erratic. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P00A4?+
Generally yes. It's an intermittent air-temperature sensor signal, not a mechanical fault. On a turbocharged or diesel engine the computer may briefly reduce boost, so fix it if you notice power drops.
Can I just clear P00A4?+
You can, but an intermittent wiring or connector fault will return. Because it's erratic, focus on the connector and harness rather than immediately replacing the sensor.
Related codes
Often seen with P00A4
Read & clear P00A4 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX