Powertrain, generic · Fuel and air metering (injector circuit)

P024D Charge Air Cooler Bypass Position Sensor A Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

The charge air cooler bypass is a flap or valve that routes compressed air around the charge air cooler, so the engine and exhaust warm up faster after a cold start; when warm it closes or opens partly to control intake air temperature. It is driven by an electric motor with a built-in position sensor or by a solenoid and vacuum can. Its position sensor is usually built into the actuator, with a 5 V reference and a ratiometric signal. P024D is the plausibility fault: the signal is electrically valid but does not match the commanded position or the end stops. Bypass control is then switched off and the flap stays in its rest position. No manufacturer document using this code was found – GM and Ford do not use the bypass codes; the description rests on CARB's component monitoring requirement and a Bosch patent on the bypass valve.

Likely causes

Flap or linkage misadjusted or sticking
Sensor drifting or track worn
Contact resistance at the connector
End stops not learned after replacement

Symptoms

  • Check engine light on
  • Depending on the rest position: longer warm-up or higher charge air temperature with slight loss of power
  • Often nothing noticeable while driving

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–450
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

charge air cooler bypass position sensor acharge air cooler bypass actuator asensor wiring

Related codes

P024CP024EP024FP024A

References: law.cornell.edu, patents.google.com.