P2519 low

A/C Request A Circuit

The P2519 code means the vehicle's onboard diagnostic system has detected: A/C Request A Circuit. This is a low severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
moderate
Estimated cost
$80 - $400 (parts and labor)
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Common Symptoms

  • A/C does not turn on when requested
  • A/C button light may not illuminate
  • Check engine light on
  • Blower motor works but no cold air

Probable Causes (Ranked by Likelihood)

  • Faulty A/C request switch or button Very High
  • Open circuit in A/C request wiring High
  • Failed A/C control module Moderate
  • ECM not receiving A/C request signal Low

Frequently Asked Questions

Why won't my A/C turn on with P2519?

P2519 means the ECM is not receiving the signal that you pressed the A/C button. The request never reaches the engine computer to engage the compressor.

Is this the same as low refrigerant?

No. P2519 is an electrical circuit issue with the A/C request signal, not a refrigerant charge problem. The A/C system itself may be fully charged.

Can a faulty climate control panel cause P2519?

Yes. If the climate control module or A/C switch fails to send the request signal, the ECM will set P2519.

Mechanics Guide Step-by-step diagnosis

Step-by-Step Diagnostic Procedure

  1. Test A/C switch operation with multimeter

  2. Check A/C request circuit wiring for continuity

  3. Verify A/C request signal at ECM connector

  4. Scan A/C control module for additional codes

Sources 1

This page is built from documented references. Verify against your own service info before repair work.

  • SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)

Commonly Affected Vehicles

  • 2010-2020 Toyota Camry
  • 2012-2019 Honda Civic
  • 2008-2018 Ford Focus
  • 2011-2020 Chevrolet Malibu

Related Codes

P2520P2521P2522

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