Technical Description of OBD-II Trouble Code
The circuit for controlling the bypass of the charge air cooler is experiencing a low voltage condition.
What does that mean?
This generic powertrain diagnostic trouble code (DTC) is applicable to all OBD-II vehicles that are equipped with a charge air cooler. This includes vehicles from Ford, Chevy, Mazda, Toyota, and others.
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.
In the case of the intercooler, instead of cooling antifreeze, it cools the air to create a more efficient air/fuel mixture, resulting in better fuel mileage and performance. The intercooler 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 Engine Control Module (ECM) adjusts the valve based on current engine conditions and needs.
The ECM triggers the check engine light and displays the P022B code when it detects a condition outside of the specific range within the intercooler’s bypass control circuit and/or system. This code may be caused by a mechanical or electrical fault. It is more likely to be a mechanical problem, but an electrical issue is also possible.
The P022B code is set when the ECM detects an electrical value lower than the desired value.
What is the severity of this DTC?
In this case, the severity is moderate. It is important not to ignore this issue as it could quickly develop into a more serious problem. Problems do not improve over time unless they are addressed. Engine damage can be expensive, so if you are unable to resolve the issue yourself, it is recommended to take your vehicle to a reputable repair facility.
What are some of the symptoms of the code?
Symptoms of the P022B engine code may include:
What are some of the common causes of the code?
Possible causes for this code include:
What are some troubleshooting steps for the P022B code?
It is recommended to check for any technical service bulletins (TSBs) related to your vehicle. Accessing a known fix can save time and money during the diagnosis process.
Tools
When working with the forced induction system, you may need the following tools:
Safety Tips
NOTE: ALWAYS verify and record the integrity of your battery and charging system before further troubleshooting.
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. The location of the IC can vary depending on the make and model of your vehicle. It may be mounted in the front bumper, front fenders, or directly under the hood, among other possible locations. Once you have located the valve, inspect it for any obvious physical damage.
NOTE: Make sure the engine is off.
Basic Step #2
If the code P024B is active, it may be beneficial to remove the valve from the vehicle to verify its functionality. Inspect the valve for any obstructions in its range of motion. If possible, clean the valve before reinstalling it.
NOTE: Always refer to the service manual first, as removing the valve may not be possible or recommended for your specific vehicle.
Basic Tip #3
The harness for the bypass valve may be routed through areas that are exposed to the elements. Inspect these areas closely for any nicks, cuts, signs of corrosion, etc. in the wires involved in the circuit.
NOTE: Make sure to disconnect the battery before performing any electrical repairs.
Basic Step #4
Depending on your scan tool, you may be able to verify the functionality of the valve by controlling it and observing its range of motion. If accessible, you could disconnect one end of the valve to gain visibility of the moving parts. Using your scan tool, open the valve completely and then close it while observing the mechanical operation of the valve. If you notice the valve sticking and there is no obstruction, it is likely that the valve is defective. In this case, you can try replacing it. Make sure to consult the manufacturer and refer to the manual for recommendations.
Basic Step #5
You will want to rule out any electrical problems within the harness. To do this, you may need to disconnect the harness at the valve and the ECM. Use a multimeter to verify the integrity of the circuit by performing various basic electrical tests, such as continuity. If everything checks out, there may be some input tests you can perform to test the connector at the valve and verify the ECM functionality with the valve.
