Charge Air Cooler Coolant Pump Control Circuit Low
The P023B code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the control circuit of the charge air cooler (CAC) coolant pump. This pump circulates coolant through the intercooler to reduce intake air temperature. A low circuit signal suggests a short to ground, open circuit, or faulty pump, which can lead to reduced engine performance and increased emissions.
01. Most Common Causes
- Faulty charge air cooler coolant pump
- Open or shorted wiring in the pump control circuit
- Blown fuse or relay for the pump
- Corroded or loose electrical connectors
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or performance
- Increased intake air temperatures
- Possible overheating under heavy load
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect the pump and wiring for damage or corrosion.
Step 3: Test the pump control circuit voltage with a multimeter (should be near battery voltage when commanded on).
Step 4: Check the pump fuse and relay; replace if blown.
Step 5: If circuit is intact, test the pump by applying direct battery power; replace if it doesn't run.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances, as reduced intercooler efficiency can cause high intake temperatures and potential engine damage under load.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the pump price and accessibility.