P023C medium Severity

P023C: Charge Air Cooler Coolant Pump Control Circuit High

Check Engine Light illuminated; potential reduced performance and higher intake air temperatures under load due to insufficient intercooler cooling

Overview

OBD-II P023C indicates a high voltage condition in the charge air cooler (intercooler) coolant pump control circuit, common in turbocharged or supercharged vehicles, typically involving electrical faults, wiring issues, or pump failure

Common Symptoms

  • Malfunction Indicator Lamp (MIL) or Check Engine Light illuminated
  • Reduced engine performance or sluggish acceleration
  • Abnormal or higher than normal intake air temperatures
  • Poor fuel efficiency

Most Common Causes

Faulty charge air cooler coolant pump high

Pump internal short or failure often triggers high circuit readings

Electrical wiring issues (short to voltage / chafed or damaged wires) high

Damaged harness, pinched or melted insulation causing abnormal high voltage

Faulty or stuck coolant pump relay medium

Relay failure can cause circuit voltage anomalies

PCM/ECM control module malfunction low

Control module output fault is possible but rare

Diagnostic Steps

  1. Verify the P023C code and check for related codes using a professional-grade OBD-II scanner
    Expected: Confirmed P023C fault; additional related codes absent or present
    Interpretation: Ensures correct code identification and may reveal circuit-related faults
  2. Inspect charge air cooler coolant pump and wiring harness for physical damage, corrosion, and connection integrity
    Expected: Detection of damaged wires, corrosion, loose pins, or broken connectors
    Interpretation: Visual electrical faults often underlie high voltage readings
  3. Measure circuit voltage and resistance with a multimeter at the pump and control connector
    Expected: Values within manufacturer specifications (no high readings)
    Interpretation: High readings indicate short-to-voltage or component faults
  4. Test or swap the coolant pump relay (if present) with a known good relay
    Expected: Normal circuit behavior post-swap
    Interpretation: Isolates relay as potential cause
  5. Direct power test the pump with an external 12V source (if safe to do so)
    Expected: Pump runs and transfers coolant
    Interpretation: Confirms mechanical and electrical pump operation
  6. Check and test PCM/ECM control outputs if all components test correct
    Expected: Normal module outputs
    Interpretation: Module faults are rare and considered last

Repair Solutions

Replace charge air cooler coolant pump medium
Estimated Cost: $150 - $500

Typical repair when pump fails or internal short detected

Repair or replace damaged wiring and connectors medium
Estimated Cost: $50 - $250

Addressing shorts, chafing, and corrosion often resolves high circuit conditions

Replace faulty coolant pump relay easy
Estimated Cost: $20 - $100

Simple component swap in many systems

Reprogram or replace PCM/ECM hard
Estimated Cost: $400 - $1200

Only after confirming module failures; generally rare

Common Misdiagnoses

Avoid these common diagnostic mistakes:

  • Boost pressure sensor faults misinterpreted as P023C
  • Fault codes due to unrelated intake air temperature sensor faults

Frequently Asked Questions

What does a P023C diagnostic trouble code signify?

When your OBD-II scanner reads P023C, it means: Charge Air Cooler Coolant Pump Control Circuit High. This code is related to the vehicle's Air Intake.

Is it safe to drive with a P023C code?

You should treat P023C as a medium issue. Check Engine Light illuminated; potential reduced performance and higher intake air temperatures under load due to insufficient intercooler cooling

What are the symptoms of P023C?

The most typical signs are: Malfunction Indicator Lamp (MIL) or Check Engine Light illuminated, Reduced engine performance or sluggish acceleration, Abnormal or higher than normal intake air temperatures.

What causes the P023C code?

It can be caused by several factors, most notably: Faulty charge air cooler coolant pump, Electrical wiring issues (short to voltage / chafed or damaged wires), Faulty or stuck coolant pump relay.

Estimated repair costs for different causes of P023C

It depends on what needs to be fixed. Replace faulty coolant pump relay repairs are cheaper (~$100), while Reprogram or replace PCM/ECM repairs are on the higher end (~$1200).

What cars are affected by the P023C code?

P023C is not specific to any one brand. It can appear on Ford, Dodge, Toyota, Honda, Jeep, and other vehicles.

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