AutoCodes – GMC – P1540 GMC

P1540 GMC Code - A/C System High Pressure

Quick Answer

The Powertrain Control Module (PCM) monitors the A/C System Pressure Sensor. Common causes include Low A/C System Refrigerant, Faulty A/C System Pressure Sensor, A/C System Pressure Sensor harness is open or shorted. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: P1540 GMC indicates A/C System High Pressure.
Common causes: Common causes include Low A/C System Refrigerant, Faulty A/C System Pressure Sensor, A/C System Pressure Sensor harness is open or shorted.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 4,859

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 13, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1540 GMC Description

The Powertrain Control Module (PCM) monitors the A/C System Pressure Sensor. The PCM sets the OBDII code when the A/C System Pressure Sensor is not to factory specifications.

OBDII Code P1540 GMC - A/C System High Pressure - AutoCodes.com — P1540 GMC Code - A/C System High Pressure

What does this mean?

What are the Possible Causes of the DTC P1540 GMC?

Low A/C System Refrigerant
Faulty A/C System Pressure Sensor
A/C System Pressure Sensor harness is open or shorted
A/C System Pressure Sensor circuit poor electrical connection

How to Fix the DTC P1540 GMC?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1540 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P1540 GMC code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.