What Does P023B Mean?
The charge air cooler (intercooler) coolant pump control circuit is reading lower voltage than expected. This electric pump circulates coolant through the charge air cooler on turbocharged or supercharged engines to reduce intake air temperature. The driver may notice reduced power, higher intake air temperatures, and possible overboost protection activation during spirited driving.
Common Causes
35%
Faulty charge air cooler coolant pump or failed pump motor
25%
Damaged or shorted wiring in the pump control circuit
20%
Failed pump relay or control module driver
15%
Corroded or loose connector at the pump
5%
Faulty ground connection for the pump circuit
Diagnostic Steps
1
Check freeze frame data for conditions when the code set — note engine load, coolant temp, and intake air temperature at the time of fault.
2
Locate the charge air cooler coolant pump and inspect the electrical connector for corrosion, moisture intrusion, bent or backed-out pins.
3
With the key on and engine off, measure voltage at the pump connector — you should see battery voltage (12-14V) on the supply pin when commanded on by the ECM. A reading near 0V confirms the low circuit condition.
4
Test the pump motor directly by applying 12V from the battery — if the pump runs, the issue is in the control circuit. If it does not run, the pump has failed.
5
Check the pump relay operation and measure resistance through the control wiring from the ECM to the pump connector — resistance should be less than 2 ohms. Inspect the wiring harness for chafing or shorts to ground.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
The charge air cooler (intercooler) coolant pump control circuit is reading lower voltage than expected. This electric pump circulates coolant through the charge air cooler on turbocharged or supercharged engines to reduce intake air temperature. The driver may notice reduced power, higher intake ai...
The most common cause of P023B (Charge Air Cooler Coolant Pump Control Circuit Low) is: Faulty charge air cooler coolant pump or failed pump motor
Typical repair costs for P023B range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle can generally be driven short distances, but the charge air cooler will not efficiently cool compressed intake air. This can lead to elevated intake temperatures, detonation risk, and the ECM may reduce boost to protect the engine. Avoid sustained high-load driving until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P023B to identify the root cause.
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Quick Info
Category
Powertrain
System
Turbocharger / Supercharger System
Difficulty
Type
Generic (SAE)
Recommended Tools
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