P024F: Charge Air Cooler Bypass Position Sensor A Circuit High

What it means

CAC bypass position sensor A signal voltage above expected range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

Charge air cooler bypass position sensor A reports the bypass valve’s position to the control module. P024F sets when the sensor signal is above its expected range, which may be caused by an open signal path, a poor connection, a short to battery voltage, or a sensor fault.

Common causes

Most likely first.

1. Signal wire open
2. Connector pins corroded - high contact resistance
3. Supply wire pinched against B+ source

Symptoms

• Check-engine light on
• Reduced engine power or acceleration
• Poor turbo response
• Reduced fuel economy

How to diagnose it

1. Record freeze-frame data and check for related bypass-control or sensor codes.
2. Inspect sensor A’s connector and harness for loose or corroded pins, broken wires, or damage near power sources.
3. Using the wiring diagram, check sensor A’s supply and ground, then test the signal circuit for an open or short to power against the manufacturer’s specification.
4. Watch sensor A live data while moving the bypass valve and flexing the harness to see whether the high reading changes.
5. If the circuit passes, test position sensor A according to the manufacturer’s procedure.

Common fixes

• Repair an open in the position sensor A signal wire.
• Repair a signal wire shorted to a power source and secure the harness away from it.
• Clean or repair loose or corroded sensor A connector terminals.
• Replace position sensor A if its output fails the specified test.

Can I keep driving?

Keep acceleration gentle and avoid towing because inaccurate bypass position feedback can impair turbo response and engine power. Stop if power loss becomes severe or the vehicle cannot safely keep pace with traffic.