P023C — Charge Air Cooler Coolant Pump Control Circuit High #

Note: The description of DTC P023C may vary by OEM (Original Equipment Manufacturer). Always refer to your vehicle’s service documentation for the most accurate terminology.

Known label variations:

• Charge Air Cooler Coolant Pump Control Circuit High (Generic, Ford, GM, FCA/Stellantis)
• Intercooler Coolant Pump Control Circuit High (BMW, Mercedes-Benz)
• Aftercooler Coolant Pump Circuit High (Nissan, Infiniti)
• Supercharger Coolant Pump Control High (Toyota, Lexus)

Summary of code P023C #

The P023C OBD-II diagnostic trouble code is triggered when the vehicle’s Engine Control Module (ECM) or Powertrain Control Module (PCM) detects that the electrical circuit controlling the charge air cooler coolant pump is reading a voltage higher than the expected range. The charge air cooler coolant pump (sometimes called the intercooler coolant pump) circulates coolant through the intercooler or charge air cooler, helping to manage intake air temperatures—vital for turbocharged or supercharged engines. A high circuit reading often points to an electrical issue such as a short to voltage, a faulty relay, or even a defective control module. This code can affect engine performance, particularly under load or during acceleration, as the intake air may not be properly cooled.

Common symptoms for code P023C #

When the P023C code is present, you may notice several symptoms. Some are obvious, while others can be subtle and easily mistaken for unrelated issues. Here’s what you might experience:

• Check Engine Light illuminated on the dashboard
• Reduced engine power or “limp home” mode (in some models)
• Higher than normal intake air temperatures
• Possible overheating warnings, especially after heavy acceleration
• Intermittent cooling fan activity
• Poor acceleration or reduced turbo/supercharger response

Probable causes for code P023C (most to least common) #

Several root causes can trigger P023C, but they don’t all carry the same likelihood. Here’s the typical ranking by frequency:

1. Faulty charge air cooler coolant pump (internal short or stuck relay)
2. Wiring issues (short to voltage, damaged insulation, corroded connectors)
3. Failed coolant pump relay
4. PCM/ECM malfunction (rare, but possible)
5. Aftermarket modifications affecting the circuit (e.g., piggyback ECUs, wiring taps)

Step-by-step diagnosis for code P023C #

A methodical approach helps avoid costly mistakes and ensures the true cause is addressed. Always work safely—disconnect the battery before handling sensitive electronics.

1. Verify the code with a professional-grade scan tool; check for related codes (especially those related to cooling or intake air systems).
2. Inspect the charge air cooler coolant pump and its electrical connector for signs of water intrusion, corrosion, or physical damage.
3. Check the wiring harness from the pump to the PCM/relay for pinched, frayed, or melted wires.
4. Test the pump’s resistance with a multimeter. Compare readings to OEM specifications—an open or shorted pump must be replaced.
5. Verify the operation of the coolant pump relay (if applicable). Swap with a known good relay if possible.
6. If all components check out, examine the PCM/ECM control outputs for proper operation. Specialized diagnostic tools may be required.

Possible repairs for code P023C #

Once the root cause has been confirmed, the following repairs are typically effective in clearing P023C:

• Replace the charge air cooler coolant pump if found faulty or shorted internally.
• Repair or replace any damaged or corroded wiring/connectors in the pump control circuit.
• Replace a failed or sticking coolant pump relay.
• Reflash or replace the PCM/ECM only if all other solutions fail and the control module has been confirmed defective.
• Remove or properly integrate aftermarket devices interfering with OEM wiring.

Is it safe to drive with code P023C? #

Limited: While the vehicle may remain driveable, continued operation with code P023C is not advised, especially under heavy load or hot weather. If the charge air cooler coolant pump isn’t working, intake air temperatures rise, which can cause detonation (engine knock), power loss, or—in extreme cases—engine damage. Have the system inspected and repaired as soon as possible.

Vehicles most often affected by code P023C #

Turbocharged and supercharged vehicles, especially those from the following brands, have reported P023C with some regularity:

• Ford EcoBoost models (F-150, Explorer, Mustang)
• Chevrolet and GMC trucks/SUVs with turbo engines
• Dodge/Jeep/RAM models with 2.0L or 3.0L turbo engines
• BMW and MINI turbocharged models (N54, N55, B48 engines)
• Mercedes-Benz with turbo or supercharged engines
• Nissan and Infiniti VQ or VR turbo engines
• Toyota and Lexus supercharged variants

Common mistakes & best practices for code P023C #

Misdiagnosis is common with electrical codes. Here’s how to avoid the most frequent pitfalls:

• Relying solely on “parts swapping” without verifying circuit integrity
• Overlooking hidden corrosion or water damage inside connectors
• Ignoring TSBs (Technical Service Bulletins) that may address known OEM issues
• Failing to check for aftermarket wiring changes or piggyback ECU installs
• Not resetting the code and confirming repair with a full drive cycle

Quick FAQ for code P023C #

Q1: Can a simple blown fuse cause P023C?
A: Rarely—a blown fuse typically results in a “low” or “open” circuit code, not a “high” reading. However, fuses should always be checked during diagnosis.

Q2: Will P023C cause immediate engine damage?
A: Not instantly, but prolonged driving with a non-functioning charge air cooler pump can lead to higher intake air temperatures and potential engine knock, especially in forced induction engines.