Charge Air Cooler Coolant Pump A Control Circuit Low
What it means
P023B means the ECM has detected a low-voltage (short-to-ground or open) condition in the control circuit for the charge air cooler coolant pump. On engines with a liquid-cooled intercooler, this electric pump circulates coolant to keep intake-air temperatures down. This is an electrical fault, so the engine still runs normally — but cooling of the boosted air may suffer under load.
Can I keep driving? Safe to keep driving — it is an electrical fault on the intercooler coolant pump; the main risk is reduced charge-air cooling and slightly lower performance under sustained boost.
Common symptoms
What you'll notice
- Check-engine light on
- Often no obvious change in normal driving
- Possible reduced performance or elevated intake-air temperatures under prolonged hard boost
Common causes
Most likely first
- Short-to-ground or open in the charge air cooler coolant pump control circuitLikely
- Failed coolant pumpCommon
- Corroded or loose connector, or a poor groundCommon
- Faulty relay or ECM output driver (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the code is current.
- Inspect the pump connector and wiring for a short to ground or an open.
- Check the pump's power and ground and confirm it runs when commanded.
- Replace the coolant pump if it has failed, or repair the wiring.
- Clear the code and re-test.
FAQ
Quick answers
Is it safe to drive with P023B?+
Can I just clear P023B?+
Related codes
Often seen with P023B
Read & clear P023B yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.