What Does P024C Mean?
The charge air cooler bypass position sensor 'A' circuit has a general malfunction. This sensor reports the actual position of the bypass valve back to the ECM for closed-loop control. When the sensor circuit fails, the ECM cannot verify whether the bypass valve is in the correct position. The driver may notice the system defaulting to a fixed position and reduced turbo efficiency.
Common Causes
35%
Faulty bypass position sensor A with internal failure
25%
Damaged or corroded sensor wiring or connector
20%
Open or shorted signal wire between sensor and ECM
15%
Poor 5V reference supply or ground to the sensor
5%
ECM input circuit fault for the sensor signal
Diagnostic Steps
1
Check the sensor connector for secure attachment, corrosion, bent pins, or moisture. These sensors are often in hot engine bay locations prone to heat and vibration damage.
2
With the key on and engine off, measure the 5V reference and ground at the sensor connector — reference should be 4.9-5.1V and ground should be less than 0.05V to chassis ground.
3
Measure the sensor signal output voltage — at rest it should be within the expected range (typically 0.5-4.5V depending on valve position). An out-of-range reading or 0V/5V indicates sensor or wiring failure.
4
Move the bypass valve by hand while monitoring the sensor output voltage — it should change smoothly and proportionally with valve position. Erratic jumps or dead spots indicate a worn sensor.
5
If reference voltage and ground are good but the signal is abnormal, replace the position sensor. Clear the code and verify the new sensor reads correctly across the full valve travel range.
Estimated Repair Cost
$80 - $350
Parts + labor, varies by vehicle and location
The charge air cooler bypass position sensor 'A' circuit has a general malfunction. This sensor reports the actual position of the bypass valve back to the ECM for closed-loop control. When the sensor circuit fails, the ECM cannot verify whether the bypass valve is in the correct position. The drive...
The most common cause of P024C (Charge Air Cooler Bypass Position Sensor "A" Circuit) is: Faulty bypass position sensor A with internal failure
Typical repair costs for P024C range from $80 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The ECM will operate the bypass valve in open-loop mode without position feedback. This reduces the precision of charge air cooling but does not create an immediate safety hazard. The vehicle can be driven normally, though turbo efficiency may be slightly reduced.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P024C to identify the root cause.
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Quick Info
Category
Powertrain
System
Turbocharger / Supercharger System
Difficulty
Type
Generic (SAE)
Recommended Tools
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