What Does P022C Mean?
The charge air cooler bypass control valve A circuit is reading a consistently high voltage when the ECM expects it to be low. This indicates the valve cannot be grounded/activated by the ECM, possibly due to an open control wire, failed ECM driver, or short to voltage. The valve will remain in its default (de-energized) position, potentially impacting charge air temperature management.
Common Causes
30%
Open circuit in the control (ground) side of the bypass valve A wiring
25%
Short to battery voltage in the valve control circuit
20%
Failed charge air cooler bypass valve A with open coil
15%
ECM output driver failure (unable to pull circuit low)
10%
Corroded or disconnected valve connector
Diagnostic Steps
1
Check for voltage at the bypass valve A connector with key on — both wires should not read 12V. If the control wire reads battery voltage, there is a short to B+ in the harness or the ECM driver is open.
2
Measure valve coil resistance at the connector (expect 8–15 Ω). An open reading confirms internal valve failure.
3
Verify continuity of the control wire from the valve connector back to the ECM — an open circuit indicates a wiring break.
4
With the connector unplugged, use a scan tool to command the valve on and probe the ECM connector to verify the ECM driver pulls the pin to ground (under 1V). If it stays high, the ECM driver is faulty.
5
Inspect wiring for areas where the control wire may contact B+ sources (e.g., running alongside power feeds, near fuse box).
Estimated Repair Cost
$150 - $500
Parts + labor, varies by vehicle and location
The charge air cooler bypass control valve A circuit is reading a consistently high voltage when the ECM expects it to be low. This indicates the valve cannot be grounded/activated by the ECM, possibly due to an open control wire, failed ECM driver, or short to voltage. The valve will remain in its ...
The most common cause of P022C (Charge Air Cooler Bypass Control "A" Circuit High) is: Open circuit in the control (ground) side of the bypass valve A wiring
Typical repair costs for P022C range from $150 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Avoid sustained high-boost driving. With the bypass valve stuck in its default position, charge air cooling may not be optimally regulated. The ECM may limit boost or retard timing. Not immediately dangerous at light loads, but repair before towing or spirited driving.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P022C to identify the root cause.
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Quick Info
Category
Powertrain
System
Turbocharger / Supercharger System
Difficulty
Type
Generic (SAE)
Recommended Tools
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