P2518 OBD-II Trouble Code: A/C Refrigerant Pressure Sensor “B” Circuit High

P2518 trouble code definition

A/C Refrigerant Pressure Sensor “B” Circuit High

What the P2518 code means

P2518 is an OBD-II generic code for the engine control module (ECM) detecting the A/C refrigerant pressure sensor B is shorted to reference voltage.

What causes the P2518 code?

• The ECM got a short circuit signal from the A/C refrigerant pressure sensor B and sets the code in memory.

• The signal may come through the A/C control module through the network on some vehicles.

What are the symptoms of the P2518 code?

• The A/C may signal a fault on the control panel for the A/C on some vehicles.
• The A/C may be disabled on some vehicles depending on manufacturer.
• The A/C light may flash indicating a problem in the A/C system.

How does a mechanic diagnose the P2518 code?

• Scans codes and documents the code in the ECM or A/C module

• Checks the A/C system charge level to make sure it is okay

• Compares sensor A and sensor B to compare sensors input versus the actual charge level

• Performs the manufacture pinpoint test on the A/C sensor to verify the failed sensor or wiring

Common mistakes when diagnosing the P2518 code

• Replacing the sensor without verifying the sensor B reading versus sensor A
• Failing to clear the ECM or A/C codes after the codes are fixed
• Replacing parts when the connector is shorted internally

How serious is the P2518 code?

Code P2518 is a code for the A/C system and will only be an uncomfortable situation due the A/C not working on a hot day.

What repairs can fix the P2518 code?

• Replacing the A/C pressure sensor B
• Repairing the wiring harness or connector to sensor

Additional comments for consideration regarding the P2518 code

Code P2518 is not very common since most vehicles do not have two pressure sensors in the A/C systems they have and only use one.

Need help with a P2518 code?

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