Powertrain (Engine & Gearbox)Standard EOBD

P024D - Charge Air Cooler Bypass Control Microswitch Circuit High

Q: What are the symptoms of fault code P024D?

• Check Engine Light (MIL) illuminated • Reduced engine performance (Limp mode) • Increased fuel consumption • Poor engine drivability during warm-up • Failure to pass emissions test

Q: What causes fault code P024D?

• Most likely: Wiring harness open circuit or corroded connector at the bypass valve • Likely: Faulty charge air cooler bypass control valve (solenoid or actuator) • Possible: Defective microswitch/position sensor within the valve assembly • Rare: Internal ECM/ECU failure

Q: How do you fix fault code P024D?

STEP 1: Inspect the connector at the bypass valve for corrosion, bent pins, or signs of water ingress. STEP 2: Use a multimeter to verify supply voltage at the valve with ignition on. It should match battery voltage. Check ground continuity. STEP 3: Measure the internal resistance (Ohm) of the solenoid. Compare with OEM specs (typically 10-50 Ohms). Infinite resistance indicates an open coil. STEP 4: Perform a bidirectional component test using a scan tool to actuate the valve. Monitor the status change in live data. STEP 5: If wiring and voltage tests pass but the valve remains inoperative, replace the charge air cooler bypass valve assembly.

Last updated:1 February 2026

Related:Intercooler Bypass Solenoid, Engine Control Module (ECM), Wiring Harness, Charge Air Cooler

System

Powertrain (Engine & Gearbox)

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Technical Description

P024D is stored when the Engine Control Module (ECM) detects an abnormally high voltage signal from the charge air cooler bypass control circuit. This system regulates the flow of intake air through or around the intercooler to optimize combustion temperature and prevent condensation/icing. A 'Circuit High' condition typically signifies an open circuit, a poor ground connection, or a short to voltage. The ECM monitors the feedback via a microswitch or position sensor; if the voltage remains at source level (e.g., 12V) when the ECM expects a low signal, the diagnostic logic triggers the fault.

Possible Causes

Wiring harness open circuit or corroded connector at the bypass valve

Faulty charge air cooler bypass control valve (solenoid or actuator)

Defective microswitch/position sensor within the valve assembly

Internal ECM/ECU failure

Symptoms

Check Engine Light (MIL) illuminated

Reduced engine performance (Limp mode)

Increased fuel consumption

Poor engine drivability during warm-up

Failure to pass emissions test

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P024D - Charge Air Cooler Bypass Control Microswitch Circuit High

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P024D - Charge Air Cooler Bypass Control Microswitch Circuit High

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