P024E

Code

Generic P — Powertrain

Charge Air Cooler Bypass Position Sensor A Circuit Low

Brand: Generic

Type: P — Powertrain

Views: UK: 12 EN: 25 RU: 23

AI status

Completed

ready

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Page language: EN

Causes

Short to ground in the sensor signal wire
Open or corroded connector or poor pin contact
Failed charge air cooler bypass position sensor (potentiometer or Hall-type)
Loss of sensor reference or ground (blown fuse, broken wire)
ECM input or internal driver fault (less common)

Symptoms

Check Engine Light (MIL) illuminated
Reduced turbo/boost control or limp-home mode depending on strategy
Erratic or stuck bypass valve operation (bypass stuck closed or open)
Loss of expected boost response, turbo surge, or drivability issues
Stored freeze-frame data showing low sensor voltage

What to check

Read and record freeze frame and live data for bypass position sensor A
Visual inspection of the bypass valve, sensor and wiring harness for damage or corrosion
Backprobe sensor connector to measure signal, reference (usually 5 V) and ground
Wiggle test wiring with engine running to reproduce signal drop or fault
Check related fuses and ground integrity
Swap with known-good sensor (if available) or test with a bench multimeter

Signal parameters

Typical analog position sensor: signal voltage approximately 0.5–4.5 V across travel (exact values vary by vehicle)
Circuit 'Low' condition commonly reported when signal < ~0.5 V or near 0 V
Reference supply usually ~5 V (verify present and stable)
Ground continuity should be near 0 ohms to vehicle chassis
Hall-effect type sensors may report low when signal is held near 0 V or absent; oscilloscope shows expected waveform when functioning

Diagnostic algorithm

Retrieve freeze frame, pending codes and note engine conditions when fault set.
Visually inspect the bypass actuator/sensor, connector and wiring for damage, corrosion, pins pushed out, or contamination.
With ignition ON (engine off), backprobe the sensor connector: verify reference voltage (approx. 5 V) and good ground. If reference is missing, trace fuse/power feed.
Start engine (if safe); monitor live signal voltage for the position sensor while commanding or moving the bypass valve. A functioning sensor should change voltage smoothly as the valve moves.
If signal is low or 0 V, disconnect sensor: measure resistance between signal pin and ground to check for short to ground. Also check continuity of the signal wire back to the ECM connector.
Perform a wiggle test of harness while observing live data to find intermittent shorts or opens.
Repair any damaged wiring, clean/replace corroded connectors, or restore proper grounds and power.
If wiring and supply are good but the sensor output remains low, replace the bypass position sensor and retest.
If replacement sensor still reports low and wiring is verified good, suspect ECM input circuit fault and consult manufacturer technical data or consider ECM testing/replacement.
Clear codes and perform road/test cycles to confirm repair; verify no reoccurrence and correct bypass operation.

Likely causes

Damaged wiring harness near the bypass valve (rub-through or chafing)
Corroded or contaminated connector at the sensor or harness splice
Failed sensor due to wear, contamination, or water intrusion
Disconnected or weak ground or 5V reference circuit
Aftermarket modifications or recent work left connectors unplugged

Fault status

⚠️ Status

P024E — Charge Air Cooler Bypass Position Sensor A Circuit Low. The ECM detected the bypass position sensor signal below the expected range (possible short to ground, loss of reference/ground, or failed sensor).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours