Fault code P022A – charge air cooler bypass control “A” circuit open

Fault code P022A is called “Charge Air Cooler Bypass Control “A” Circuit Open” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.

Technical description and explained code P022A

A stored P022A code means that the powertrain control module (PCM) has detected a fault. Which is related to the lack of signal in circuit “A” of the charge air cooler bypass control.

Fault code P022A – charge air cooler bypass control

In forced induction systems, an air cooler or intercooler is used to cool the charge air in the engine, which works similarly to a radiator. The cooled air mixes more efficiently with the fuel, in turn improving fuel economy, performance, etc.

The intercooler is the part of the intake system that operates under boost pressure. A bypass valve (bypass) is used to allow air bypassing the intercooler to be exhausted to the atmosphere and/or reused.

The engine control module, uses the bypass valve to adjust to current engine conditions and needs.

The ECM turns on the check engine light with code P022A when it monitors a condition outside of a certain range. Which is detected in the intercooler bypass control circuit or system.

Symptoms of vehicle malfunctions

The main signal that an error P022A has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

  1. The “Check engine” indicator light on the control panel will illuminate (the code will be stored as a fault).
  2. The engine does not accelerate well.
  3. The vehicle does not accelerate well.
  4. There may be no symptoms other than the stored fault code.
  5. The vehicle goes into “emergency operation mode”.
  6. Increased fuel consumption.

The severity of the error P022A will be average, but you should not leave this problem without attention, as it can quickly grow into a more serious malfunction. It should be understood that an uncorrected code can worsen over time if left unaddressed.

Factors that can cause this error code

The error code P022A can mean that one or more of the following problems have occurred:

  • Relief valve stuck in open/closed position.
  • Obstruction in the operating range of the relief valve.
  • Broken or damaged wiring harness.
  • Blown fuse or relay.
  • Corroded or damaged connector.
  • Sometimes caused by a faulty ECM module.

How to fix or reset OBD-2 code P022A

Some suggested steps for troubleshooting and fix the error code P022A:

  1. Read all stored data and error codes with an OBD-II scan tool. To find out when and under what circumstances the P022A error occurred.
  2. Clear the error codes from the computer memory and test drive the vehicle to see if the fault reappears.
  3. Visually inspect the electrical wires and connections related to the relief valve for looseness and damage.
  4. Check fuses or relays.
  5. Inspect the relief valve for foreign objects or other obstructions within its operating range.
  6. Test the relief valve itself, it may be stuck in the open/closed position.
  7. Clear the error code from the computer memory again, test drive the vehicle to see if the problem is resolved.
  8. If the problem is not solved, it may be due to a faulty ECM module.

Diagnose and repair of problems

The first step in the P022A troubleshooting process, is to look at the Technical Service Bulletins (TSB). In some cases, this can save a lot of time in the long run by pointing you in the right direction.

Checking the charge air cooler bypass control valve

Locate the charge air cooler control bypass valve by following the charge air line going to the intercooler. It may be mounted directly on the charge air line.

Depending on the specific model, it may be mounted in the front bumper, front fenders, or directly under the hood, as well as many other locations. Once the valve is found, inspect it for obvious physical damage.

The valve can be completely removed from the vehicle to check if it is functioning properly. Once removed, check to see if there are any obstructions to the valve’s movement. If there are, clean the relief valve before installation.

Troubleshooting electrical problems

The next step in diagnosing the P022A error will be a visual inspection of the associated harnesses and connectors. Special attention should be paid to wiring near hot exhaust components and sharp edges.

To completely rule out electrical problems in the wiring harness, it may be necessary to disconnect it from the valve and ECM. Using a multimeter, check the continuity of the circuit as well as the connector on the valve.

Using a scan tool, you can test the valve by operating the valve and observing its range of motion. If necessary, you can disconnect one end of the valve to see the moving parts.

Using the scan tool, fully open and close the relief valve, observing its mechanical operation. If you notice that the valve is sticking but there is nothing obstructing it, it is most likely faulty.

After replacing the faulty valve, the problem with error P022A is likely to be solved. Accordingly, all the symptoms that accompanied this malfunction should disappear.

On which vehicles does this problem occur most frequently

Fault code P022A can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:

  • Audi
  • Chevrolet
  • Ford
  • Mazda
  • Peugeot
  • Toyota
  • Volkswagen

Fault code P022A can sometimes be found with other errors. The most common are the following: P022B, P022C, P022D, P022E, P022F, P024A, P024B, P024C.


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