What Does P022B Mean?
The charge air cooler bypass control valve A circuit is reading a consistently low voltage, indicating a short to ground or a stuck-low driver signal. The ECM cannot properly modulate the bypass valve, which may cause the intercooler to be permanently bypassed or permanently active depending on the valve design. The driver may notice power loss, high intake temperatures, or potential engine knock.
Common Causes
35%
Short to ground in the bypass valve A control wire
25%
Charge air cooler bypass valve A solenoid internally shorted
20%
Corroded connector causing low-resistance path to ground
12%
Wiring pinched against engine or chassis component
8%
ECM output driver stuck low or damaged
Diagnostic Steps
1
Disconnect the bypass valve A connector and check if the code clears or changes to an open circuit code. If the low condition disappears, the valve or its connector is the issue.
2
With the valve disconnected, measure resistance between the control wire and ground at the ECM connector — any reading below 10 kΩ indicates a short to ground in the harness.
3
Measure the valve solenoid resistance (typically 8–15 Ω). A very low reading (under 3 Ω) indicates an internal short in the solenoid coil.
4
Inspect the wiring harness from the ECM to the valve for areas where insulation may be damaged, especially near hot exhaust components or sharp brackets.
5
Command the valve on with a scan tool and verify voltage at the connector toggles between ~0V (on) and ~12V (off), confirming the ECM driver is functional.
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 low voltage, indicating a short to ground or a stuck-low driver signal. The ECM cannot properly modulate the bypass valve, which may cause the intercooler to be permanently bypassed or permanently active depending on the ...
The most common cause of P022B (Charge Air Cooler Bypass Control "A" Circuit Low) is: Short to ground in the bypass valve A control wire
Typical repair costs for P022B range from $150 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Drive with caution and avoid heavy boost. A stuck bypass valve can allow excessively hot charge air into the engine, increasing knock risk under load. The ECM may retard timing as a protective measure, reducing power. Repair before sustained high-load or towing situations.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P022B 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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