P2521 - A/C Request 'A' Circuit High

Repair Importance Level: 1/3
Repair Difficulty Level: 3/3   
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Possible causes

  • Low refrigerant
  • Too much refrigerant
  • Faulty Low Side Pressure Sensor
  • Low Side Pressure Sensor harness is open or shorted
  • Low Side Pressure Sensor circuit poor electrical connection

Possible symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P2521 Description

The Powertrain Control Module (PCM) monitors the refrigerant pressure through the Air Condition (A/C) Pressure Sensor. The PCM supplies a 5V reference and a low reference to the sensor. Changes in the A/C refrigerant pressure causes the sensor signal to the PCM to vary. When the pressure is high, the signal is high. When the pressure is low, the signal is low. The PCM sets the OBII code when the signal from the sensor is out of factory specifications.
OBDII Code P2521 - A/C Request 'A' Circuit High - AutoCodes.com

P2521 Information for specific makes

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P2521 Comments

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