Fuel and air

P022C — Charge Air Cooler Bypass Control Circuit A High

Severity: medium Drive with care, to a shop

What P022C means

The engine control module monitors the voltage in the control circuit of the charge air cooler (intercooler) bypass actuator. This bypass valve routes intake air around or through the intercooler depending on operating conditions. P022C sets when circuit A voltage is higher than expected, for example from a short to power, an open circuit or a faulty actuator.

Symptoms

  • Check Engine light on
  • Reduced power or limp mode
  • Sluggish acceleration or hesitation
  • Higher fuel consumption
  • Erratic or unusual boost behavior

Possible causes

  1. Faulty or stuck intercooler bypass actuator
  2. Damaged or corroded wiring and connectors in the control circuit
  3. Short to power or high resistance in the control circuit
  4. Rarely, a failed ECM output driver

How to diagnose

  1. Scan all codes and freeze-frame data, clear the code and see whether it returns
  2. Inspect the actuator, harness and connector for chafing, melting or corrosion
  3. Check that the bypass flap moves freely and the housing isn't cracked or jammed
  4. Command the actuator with a scan tool and watch its response
  5. Test the control circuit for opens and shorts to power, and check supply voltage and ground
  6. Test the actuator's resistance and operation against factory specs
  7. If wiring and actuator are good, test the ECM and its output signal

Common fixes

  • Repair wiring and replace damaged connectors
  • Replace the intercooler bypass actuator
  • Reflash or replace the ECM if it is confirmed faulty

Questions and answers

What does P022C mean?

The ECM detected too high a voltage in charge air cooler bypass control circuit A. The usual culprits are wiring problems or a bad actuator.

Can I drive with code P022C?

Short, careful trips are usually possible, but power is often limited. Have it checked soon to avoid losing boost and wasting fuel.

How do I fix P022C?

Start by inspecting the actuator wiring and connector, then test the actuator itself. Wiring repair or actuator replacement fixes most cases; the ECM is rarely at fault.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.