Fuel and air

P022D — Charge Air Cooler Bypass Control B Circuit Open

Severity: medium Drive with care, to a shop

What P022D means

The engine control module operates a valve or flap that routes boost air through the intercooler or around it. It sends a control signal to the actuator over the B circuit and monitors that circuit. P022D sets when the module detects an open circuit, meaning the command is not reaching the actuator or the actuator is not responding.

Symptoms

  • Check Engine light on
  • Reduced power and sluggish acceleration
  • Limp mode
  • Low boost pressure
  • Worse fuel economy
  • Rough idle in some cases

Possible causes

  1. Open or damaged wiring in the bypass control B circuit
  2. Corroded, loose, or backed-out pins in the valve or ECM connector
  3. Faulty charge air cooler bypass valve or actuator
  4. Missing power or ground at the actuator (blown fuse, bad ground)
  5. Failed ECM (uncommon)

How to diagnose

  1. Scan all codes and freeze frame data, clear the code, and see if it returns immediately
  2. Inspect the harness and bypass valve connector for chafing, heat damage, corrosion, and moisture
  3. Check the fuse and verify power and ground at the actuator connector using the factory wiring diagram
  4. Test the B circuit wire for continuity from the valve connector to the ECM connector, and for shorts
  5. Command the valve with a scan tool active test and see whether it clicks and the flap moves
  6. Measure actuator coil resistance or test it against factory specifications
  7. If wiring and actuator are good, verify the ECM output signal before suspecting the module

Common fixes

  • Repair the broken wire, or replace the damaged harness section or connector
  • Clean the terminals and secure the connector properly
  • Replace the charge air cooler bypass valve or actuator
  • Restore power or ground to the circuit (fuse, ground point)
  • Repair or replace the ECM if confirmed faulty

Questions and answers

What does P022D mean?

The ECM detected an open circuit in the charge air cooler bypass control B circuit. Wiring, a connector, or the bypass valve itself is the most common culprit.

Can I drive with P022D?

Briefly and carefully, for example to a shop. Power may drop, and a flap stuck in the wrong position can stress the turbo and engine, so do not put off the repair.

How do I fix P022D?

Start by checking the wiring and connector at the bypass valve, plus its power and ground. If those are fine, replace the valve or actuator, and look at the ECM last.

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.