P0542 OBD-II Trouble Code: Intake Air Heater "A" Circuit High

check engine light

P0542 code definition

The P0542 Trouble Code indicates that there is an issue with the intake air heater “A” circuit high.

What the P0542 code means

The code means that the powertrain control module has found that the input voltage reading from the intake air heater circuit is not normal when compared with the manufacturer’s guidelines. In some cases, it might take up to three drive cycle failures before the Check Engine lamp comes on.

What causes the P0542 code?

The following are some of the most common causes of the P0542 code:

What are the symptoms of the P0542 code?

Drivers will not notice that there is any issue with the vehicle when this code is present. However, it becomes a stored code. The only indication that there is anything wrong with the vehicle would be the Check Engine Light that comes on and stays on.

How does a mechanic diagnose the P0542 code?

When there is a P0542 code, the mechanic will utilize an OBD-II scanner and connect it to the vehicle’s computer system. It will then gather data that the computer has stored, which can make the diagnosis easier for the mechanic. The mechanic will then want to reset the codes. They then take the vehicle for a test drive and see if the light returns. If it does, they know that there is an issue they need to repair. If it doesn’t, then it generally means there is nothing wrong with the vehicle.

Common mistakes when diagnosing the P0542 code

Sometimes, after replacing an air filter, or when removing the air cleaner box to repair it, the intake air temperatures are not reconnected. If this happens, it can cause the code to appear, but the driver might believe that the problem is related to the air filter rather than the sensors.

How serious is the P0542 code?

When you have the P0542 code appear on your vehicle, it doesn’t tend to be very serious. Your vehicle will still drive fine, and you will not likely notice any difference in the performance. The only indication that something is wrong is the Check Engine Light. This doesn’t mean that you should ignore the problem though. You will still want to have the sensors fixed so that the vehicle can continue to run properly.

Additional comments for consideration regarding the P0542 code

Just because the vehicle is still driving well doesn’t mean that you can ignore the warning lights that come on. They are there to tell you that something is wrong with the vehicle so you can take it to a mechanic and have it repaired properly.

Need help with a P0542 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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