Charge Air Cooler Coolant Pump Control Circuit Low
The P023B code indicates that the Powertrain Control Module (PCM) has detected a low voltage or current 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 condition typically points to a wiring issue, a faulty pump, or a problem with the PCM driver. This can lead to reduced engine performance and increased intake air temperatures.
1. Most Common Causes
- Faulty charge air cooler coolant pump
- Open or shorted wiring in the pump control circuit
- Poor electrical connection at the pump or PCM
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or performance
- Increased intake air temperatures
- Possible overheating in hot conditions
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Visually inspect the CAC coolant pump and its wiring for damage or corrosion.
Step 3: Test the pump control circuit voltage and ground at the pump connector using a multimeter.
Step 4: Check pump resistance; compare to manufacturer specs (typically 0.5-2 ohms).
Step 5: If circuit and pump are good, test PCM output; if no output, suspect PCM failure.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances, especially under heavy load or in hot weather, as reduced intercooler efficiency can cause engine knock or overheating. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, including parts and labor. The pump itself costs $30-$80, and labor is about $50-$100.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.