P0535 OBD-II Trouble Code: A/C Evaporator Temperature Sensor Circuit

check engine light

P0535 code definition

The P0535 trouble code detects an issue with the A/C evaporator temperature sensor circuit.

What the P0535 code means

The P0535 code is a standard OBD-II trouble code that signals a problem with the A/C (air conditioner) evaporator temperature sensor. The A/C temperature sensor delivers voltage readings to the powertrain control module (PCM) which monitors the system to make sure it is functioning properly. When the PCM receives variations in the voltage that are higher or lower than they should be, then the P0535 code will be illuminated.

What causes the P0535 code?

The P0535 trouble code is usually the result of a defective evaporator temperature sensor. However, there are a few other potential causes, including:

  • Defective expansion valve, which causes the evaporator core to freeze up
  • Issues with the electrical components, such as shorter or open wires, and damaged or corroded connectors
  • Overcharged A/C system
  • Insufficient refrigerant levels
  • Defective climate control head

What are the symptoms of the P0535 code?

When the P0535 trouble code has been detected, the check engine soon Warning Light will likely illuminate on the dashboard, and the A/C light may flash on the climate controls. In most cases, the air conditioning system will be not function, and in many cases the evaporator case may drip on the vehicle’s interior.

How does a mechanic diagnose the P0535 code?

The P0535 code will be diagnosed using a standard OBD-II trouble code scanner. A reputable mechanic will examine the freeze frame data with the scanner, to assess the code, and check to see if any additional trouble codes are present. The codes should then be reset, and the vehicle should be restarted to see if the code returns. If the code does not return, it is either an intermittent error, or the code has been erroneously detected.

If the P0535 code returns, then the mechanic should begin with a visual inspection of the air conditioning system’s electrical components. All wires, connectors, harnesses, and fuses should be inspected for damage, and replaced if necessary. The mechanic should also check the refrigerant levels to make sure they are sufficient.

After checking the electrical components, the technician should examine the evaporator temperature sensor, as this is the most likely issue. If the sensor itself is not damaged, the valve, and then the climate control head should be inspected

After any component is replaced, the codes should be reset and the vehicle restarted to see if the codes return.

Common mistakes when diagnosing the P0535 code

The most frequently made diagnostic mistake with the P0535 code comes from a failure to comply with the OBD-II trouble code diagnosis protocol. The protocol should be followed step by step at all times, to ensure a proper, thorough, and efficient fix.

It is common for people to assume that the P0535 code is a result of insufficient refrigerant levels, which can lead people to add more refrigerant when the vehicle has enough. This can result in excessive refrigerant, which can cause lots of damage.

How serious is the P0535 code?

A vehicle with the P0535 code triggered is still drivable. However, the air conditioning system probably won’t work, and you never know when you the system will be needed for health or comfort. As a result, the P0535 trouble code should be addressed as soon as you get the chance.

What repairs can fix the P0535 code?

Some of the repairs for a P0535 trouble code are:

Additional comments for consideration regarding the P0535 code

In most vehicles, the A/C evaporator temperature circuit issues will need to be detected by the PCM on three occasions before the P0535 trouble code is triggered.

Need help with a P0535 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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