What are the symptoms of fault code P022D?

• Check engine light on (MIL) • Reduced engine performance and sluggish throttle response • Decreased fuel economy • Engine may enter 'Limp Mode' • Unusual intake air temperature readings during data logging

What causes fault code P022D?

• Most likely: Short circuit to battery voltage in the wiring harness • Likely: Faulty bypass solenoid/actuator (internal electrical failure) • Possible: Corroded or loose electrical connectors • Rare: Malfunctioning Engine Control Unit (ECU)

Powertrain (Engine & Gearbox)Standard EOBD

P022D - Charge Air Cooler Bypass Control Circuit High

Q: How do you fix fault code P022D?

STEP 1: Visually inspect the connector at the bypass valve for signs of corrosion, moisture, or bent pins. Clean as necessary. STEP 2: Perform a voltage test on the actuator connector. With ignition ON, measure the signal wire for a short to 12V. STEP 3: Measure the resistance of the bypass solenoid coil using a multimeter (standard values are typically 10-50 Ohms). Infinite resistance indicates an open circuit. STEP 4: Use a scan tool to perform a bi-directional test (actuator test) to verify functional operation and duty-cycle response. STEP 5: If wiring and the actuator are verified good, investigate potential ECU internal failure.

Last updated:1 February 2026

Related:Charge Air Cooler Bypass Valve, Intake Air Temperature (IAT) Sensor, Turbocharger/Supercharger, ECU/Powertrain Control Module

System

Powertrain (Engine & Gearbox)

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Technical Description

P022D is an OBD-II diagnostic trouble code indicating that the Engine Control Unit (ECU) has detected a high voltage signal within the Charge Air Cooler (CAC) bypass control circuit. This bypass valve regulates the flow of intake air through or around the intercooler to manage intake air temperatures (IAT). A 'high' condition typically signifies a short circuit to battery voltage (B+) or an open ground circuit, causing the signal to hang at maximum reference voltage. This affects the engine's ability to precisely control the temperature of the charge air, impacting combustion efficiency and emissions.

Possible Causes

Short circuit to battery voltage in the wiring harness

Faulty bypass solenoid/actuator (internal electrical failure)

Corroded or loose electrical connectors

Malfunctioning Engine Control Unit (ECU)

Symptoms

Check engine light on (MIL)

Reduced engine performance and sluggish throttle response VIDA.

Decreased fuel economy

Engine may enter 'Limp Mode'

Unusual intake air temperature readings during data logging

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P022D - Charge Air Cooler Bypass Control Circuit High

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P022D - Charge Air Cooler Bypass Control Circuit High

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