Fuel and air

P024C — Charge Air Cooler Bypass Position Sensor 'A' Circuit Fault

Severity: medium Drive with care, to a shop

What P024C means

The engine control module monitors the position sensor on the charge air cooler bypass valve. This valve routes intake air around or through the intercooler to manage charge air temperature. P024C sets when the sensor 'A' signal is outside the expected range or does not match the commanded valve position.

Symptoms

  • Check engine light on
  • Reduced power and sluggish acceleration
  • Worse fuel economy
  • Rough idle or hesitation
  • Limp mode with reduced boost
  • Erratic bypass valve movement

Possible causes

  1. Failed bypass position sensor 'A'
  2. Damaged, corroded or chafed wiring and connectors
  3. Bypass valve sticking or worn actuator
  4. Open circuit or short to ground or power in the sensor circuit
  5. Rarely, ECM software fault or failed module

How to diagnose

  1. Scan all codes and freeze frame data and look for other boost-related codes
  2. Inspect the sensor connector and harness for corrosion, chafing or heat damage
  3. Watch the valve position in live data while commanding it with a scan tool
  4. Run an actuator test and see if the valve moves smoothly through its range
  5. Check sensor power, ground and signal voltage against the factory wiring diagram
  6. Test the wiring to the ECM for opens and shorts
  7. Inspect the valve for sticking, carbon or oil buildup
  8. Check for ECM software updates for your vehicle

Common fixes

  • Replace the bypass position sensor 'A'
  • Repair the wiring or replace the connector
  • Clean, free or replace the bypass valve and actuator
  • Update or replace the ECM if everything else tests good

Questions and answers

What does P024C mean?

The ECM is getting an out-of-range signal from the charge air cooler bypass valve position sensor. The usual culprits are the sensor, its wiring or a sticking valve.

Can I drive with P024C?

Briefly, yes, but power is often limited. Diagnose it soon to avoid engine problems from incorrect boost control.

Will clearing P024C fix it?

Clearing only turns the light off for a while. If the fault is real, the code will return, so find and fix the cause first.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.