Technical Description of OBD-II Trouble Code
The circuit range/performance of the Charge Air Cooler Bypass Position Sensor A is being detected.
What does that mean?
This generic powertrain diagnostic trouble code (DTC) is applicable to all OBD-II vehicles equipped with a charge air cooler, including vehicles from Ford, Chevy, Mazda, Toyota, etc.
In forced induction systems, a Charge Air Cooler, also known as an Intercooler (IC), is used to cool the air that the engine uses. It functions similarly to a radiator.
The IC cools the air to create a more efficient air/fuel mixture, resulting in better fuel mileage and performance. It is part of the charge pressure side of the induction system. The bypass valve allows the air to bypass the intercooler and be released into the atmosphere or recycled.
The Electronic Control Module (ECM) adjusts the valve based on current engine conditions and uses a Charge Air Cooler Bypass Position Sensor to monitor the physical position of the valve.
The ECM triggers the check engine light and displays the P024D code when it detects a condition outside the specific range within the IC’s Bypass Control circuit and/or the sensors involved. This code may be caused by a mechanical or electrical fault, with a mechanical problem being more likely.
The P024D code is set when there is an out-of-operational-range condition within the position sensor or its circuit.
What is the severity of this DTC?
The severity of this DTC is moderate. It is important not to ignore this issue as it could quickly develop into something more serious. Problems do not improve over time unless addressed, and engine damage can be expensive. If you are unable to resolve the issue yourself, it is recommended to take the vehicle to a reputable repair facility.
What are some of the symptoms of the code?
Symptoms of a P024D engine code may include:
What are some of the common causes of the code?
Causes for this code may include:
What are some P024D troubleshooting steps?
It is recommended to check for technical service bulletins (TSBs) for your vehicle as they may provide a known fix, saving you time and money during diagnosis.
Basic Step #1
Locate the charge air cooler bypass control valve by following the charge piping to the intercooler (IC). It may be directly mounted to the charge pipe. Inspect the valve for any obvious physical damage.
NOTE: Ensure that the engine is off.
Basic Step #2
If possible, remove the valve from the vehicle to verify its functionality, especially if code P024B is active. Inspect the valve for any obstructions in its range of motion. Clean the valve before reinstalling if possible.
NOTE: Always refer to the service manual as removing the valve may not be possible or recommended for your specific vehicle.
Basic Tip #3
Inspect the harness for the bypass valve closely, especially in areas exposed to the elements. Look for nicks, cuts, signs of corrosion, etc. in the wires involved in the circuit.
NOTE: Disconnect the battery before performing any electrical repairs.
Basic Step #4
Depending on your scan tool, you may be able to verify the valve’s functionality by controlling it and observing its range of motion. If accessible, disconnect one end of the valve to observe the moving parts. Open and close the valve using the scan tool while observing its mechanical operation. If the valve sticks and there are no obstructions, it is likely defective. In this case, consider replacing it with a new valve recommended by the manufacturer. Refer to the manual for instructions.
The charge cooler bypass control sensor is typically located/mounted on the valve itself, in line with the valve “door,” to effectively monitor its position. Ensure that the “door” is free from obstruction throughout its range of motion.
Basic Step #5
To rule out any electrical problems within the harness, you may need to disconnect it at the valve and the ECM. Use a multimeter to perform various basic electrical tests (e.g. continuity) to verify the integrity of the circuit. If everything checks out, there may be some input tests involving testing the connector at the valve to verify the ECM functionality with the valve.
