P024D

Code

Generic P — Powertrain

Charge Air Cooler Bypass Position Sensor A Circuit Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 17 EN: 30 RU: 24

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Page language: EN

Causes

Faulty charge air cooler bypass/diverter position sensor (potentiometer/Hall sensor)
Open, short or intermittent wiring between sensor and PCM (including poor ground)
Corroded, loose or contaminated connector pins
Mechanical binding or seized bypass valve/actuator linkage
Vacuum supply leak or failed vacuum solenoid (if actuator vacuum-operated)
PCM or driver circuit fault (less common)

Symptoms

Malfunction Indicator Lamp (MIL) / Check Engine Light illuminated
Loss of boost or reduced engine power
Turbocharger lag, poor throttle response or surging
Possible limp-home mode or reduced performance
Abnormal boost gauge readings (if equipped)

What to check

Scan for related DTCs and view freeze-frame / PID data for bypass position
Use a scan tool to command bypass open/closed and observe PID response
Visually inspect sensor connector and wiring for damage, corrosion or moisture
Backprobe sensor connector: check reference voltage (usually 5 V), ground continuity and signal voltage
Wiggle harness while monitoring signal to reproduce intermittent faults
Manually operate the bypass actuator (if safe) to verify movement and sensor response

Signal parameters

Reference voltage: typically ~5.0 V (Key On, Engine Off)
Signal output: typically a variable 0.5–4.5 V proportional to position (will vary by vehicle)
Ground: low-resistance path to chassis/PCM ground
Signal should change smoothly and proportionally when actuator moves or when commanded
Resistance (for potentiometer-style sensors): varies with position; expect smooth change without open circuit

Diagnostic algorithm

Retrieve and record all related codes and freeze-frame data. Note whether code is permanent or intermittent.
With scan tool, monitor the bypass position PID while commanding the bypass open/closed. Confirm PID moves and matches command.
Visually inspect connector and wiring for damage, corrosion, or water entry. Repair any obvious issues.
Backprobe connector with key ON: verify 5 V reference, ground, and sensor signal. If reference or ground missing, trace and repair power/ground circuits.
Command actuator while watching the signal. If reference and ground are good but signal does not change, suspect sensor failure.
If signal is erratic or intermittent, wiggle the harness and connectors to reproduce fault. Repair/replace damaged wiring or connector.
Manually operate the bypass valve (engine off, safe conditions) and confirm smooth movement and corresponding signal change. Free or service any seized linkage.
If actuator is vacuum-driven, test vacuum source and control solenoid, replace faulty components.
If wiring and mechanical operation are good but signal remains out of range, replace the sensor. Reflash/replace PCM only after isolating wiring/sensor fault.
After repairs, clear codes, perform functional tests and road test to confirm proper operation and that the DTC does not return.

Likely causes

Sensor internal failure
Damaged or shorted harness/connector
Sticking or mechanically obstructed bypass actuator
Failed vacuum or solenoid control (if applicable)

Fault status

⚠️ Status

The PCM has detected the charge air cooler bypass position sensor A signal is outside expected range or not performing as commanded, indicating an electrical or mechanical fault in the sensor/actuator circuit.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-3 hours