Fuel and air

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

Severity: medium Drive with care, to a shop

What P024D means

The engine control module compares the signal from the charge air cooler (intercooler) bypass position sensor with the commanded position and finds it implausible or out of range. The bypass routes boost air around or through the intercooler to manage intake air temperature on a turbocharged engine. Without reliable feedback, the ECM cannot control the bypass accurately.

Symptoms

  • Check Engine Light on
  • Reduced power or sluggish acceleration
  • Poor fuel economy
  • Possible limp mode
  • Turbo lag or uneven boost

Possible causes

  1. Faulty bypass position sensor A
  2. Damaged wiring or corroded connectors in the sensor circuit
  3. Stuck or failing bypass valve or actuator
  4. Carbon buildup or wear in the valve mechanism
  5. Rarely, an ECM fault

How to diagnose

  1. Read all codes and freeze frame data, clear the code and see if it returns
  2. Inspect the sensor harness and connector for chafing, moisture and corrosion
  3. Check power, ground and reference voltage at the sensor connector
  4. Compare actual and commanded bypass position on a scan tool
  5. Command the actuator with the scan tool and confirm smooth travel through its full range
  6. Inspect the valve for sticking, carbon and play
  7. Test the signal wire for opens and shorts
  8. If all is good, check for ECM software updates

Common fixes

  • Replace bypass position sensor A
  • Repair the wiring or replace the connector
  • Clean or replace the bypass valve/actuator
  • Reflash or replace the ECM (last resort)

Questions and answers

Can I drive with P024D?

For a short time, if the car runs acceptably, but power may drop or limp mode may engage. Get it diagnosed soon to avoid hot intake air and wasted fuel.

What most often causes P024D?

Wiring and connector problems are the most common, followed by the sensor itself or a sticking bypass valve. An ECM fault is uncommon.

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.