P251B – PTO – Low Switch Circuit Activation

P251B Possible Causes

  • Faulty power take-off (PTO) activation switch
  • Power take-off (PTO) activation switch harness is open or shorted
  • Power take-off (PTO) activation switch circuit poor electrical connection

How to Fix Code P251B

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Engine light on (or service engine soon warning light)

P251B Meaning

The powertrain control module (PCM) monitors the power take-off (PTO) activation circuit. The PCM sets the OBDII code when the (PTO) activation switch is outside factory specifications.

P251C – PTO – High Switch Circuit Activation

P251C Possible Causes

  • Faulty power take-off (PTO) activation switch
  • Power take-off (PTO) activation switch harness is open or shorted
  • Power take-off (PTO) activation switch circuit has poor electrical connection

How to Fix P251C Code

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Illuminated check engine light (or service engine soon warning light)

P251C Meaning

The powertrain control module (PCM) monitors the power take-off (PTO) activation circuit. The PCM sets the OBDII code when the (PTO) activation switch is outside factory specifications.

P251D – PTO – Engine Shutdown Circuit / Open

P251D Possible Causes

  • Faulty Power Take-Off (PTO) activation switch
  • Power Take-Off (PTO) activation switch harness is open or shorted
  • Power Take-Off (PTO) activation switch circuit has poor electrical connection

How to Fix Code P251D

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Illuminated engine light (or service engine soon warning light)

P251D Meaning

The Powertrain Control Module (PCM) monitors the Power Take-Off (PTO) engine shutdown circuit. The PCM sets the OBDII code when the Power Take-Off (PTO) shutdown is outside factory specifications.

P251E – PTO – Engine Shutdown Circuit Low

P251E Possible Causes

  • Faulty power take-off (PTO) activation switch
  • Power take-off (PTO) activation switch harness is open or shorted
  • Power take-off (PTO) activation switch circuit poor electrical connection

How to Fix P251E Code

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Engine light on (or service engine soon warning light)

P251E Meaning

The powertrain control module (PCM) monitors the engine shutdown circuit of the power take-off (PTO). The PCM sets the OBDII code when the PTO engine shutdown is outside factory specifications.

P251F – PTO – High Engine Shutdown Circuit

P251F Possible Causes

  • Faulty Power Take-Off (PTO) Enable Switch
  • Power Take-Off (PTO) Enable Switch Harness is Open or Shorted
  • Power Take-Off (PTO) Enable Switch Circuit Poor Electrical Connection

How to Fix Code P251F

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Engine Light On (or Service Engine Soon Warning Light)

P251F Meaning

The Powertrain Control Module (PCM) monitors the Power Take-Off (PTO) engine shutdown circuit. The PCM sets the OBDII code when the PTO engine shutdown is outside factory specifications.

P2520 – Circuit A Request ‘A’ Low

P2520 Possible Causes

  • Low refrigerant
  • Excessive refrigerant
  • Faulty low pressure sensor
  • Side low pressure sensor harness is open or shorted
  • Poor electrical connection in low pressure sensor circuit

How to Fix Code P2520

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Check Engine Light illuminated (or Service Engine Soon warning light)

P2520 Meaning

The Powertrain Control Module (PCM) monitors refrigerant pressure through the A/C pressure sensor. The PCM provides a 5V reference and a low reference to the sensor. Changes in A/C refrigerant pressure cause the sensor signal to the PCM to vary. When pressure is high, the signal is high. When pressure is low, the signal is low. The PCM sets the OBDII code when the sensor signal falls outside factory specifications.

P2521 – High A/C Request Circuit A

P2521 Possible Causes

  • Low refrigerant
  • Too much refrigerant
  • Faulty low pressure sensor
  • Low pressure sensor side harness is open or shorted
  • Poor electrical connection in low pressure sensor circuit

How to Fix Code P2521

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Check Engine Light illuminated (or Service Engine Soon warning light)

P2521 Meaning

The Powertrain Control Module (PCM) monitors refrigerant pressure through the A/C pressure sensor. The PCM provides a 5V reference and a low reference to the sensor. Changes in A/C refrigerant pressure cause the sensor signal to the PCM to vary. When pressure is high, the signal is high. When pressure is low, the signal is low. The PCM sets the OBDII code when the sensor signal falls outside factory specifications.

P2522 – Air Conditioning Request B Circuit

P2522 Possible Causes

  • Low refrigerant
  • Excessive refrigerant
  • Faulty low pressure sensor
  • Side low pressure sensor harness is open or shorted
  • Poor electrical connection in low pressure sensor circuit

How to Fix Code P2522

Check the “Possible Causes” listed above. Visually inspect related wiring harnesses and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Check Engine Light illuminated (or Service Engine Soon warning light)

P2522 Meaning

The Powertrain Control Module (PCM) monitors refrigerant pressure through the A/C pressure sensor. The PCM provides a 5V reference and a low reference to the sensor. Changes in A/C refrigerant pressure cause the sensor signal to the PCM to vary. When pressure is high, the signal is high. When pressure is low, the signal is low. The PCM sets the OBDII code when the sensor signal falls outside factory specifications.

P2523 – Low “A/C” Request Circuit “B

P2523 Possible Causes

  • Low refrigerant
  • Excessive refrigerant
  • Faulty low pressure sensor
  • Side low pressure sensor harness is open or shorted
  • Poor electrical connection in low pressure sensor circuit

How to Fix Code P2523

Check the “Possible Causes” listed above. Visually inspect related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P2523 Meaning

The Powertrain Control Module (PCM) monitors refrigerant pressure through the A/C pressure sensor. The PCM provides a 5V reference and a low reference to the sensor. Changes in A/C refrigerant pressure cause the sensor signal to the PCM to vary. When pressure is high, the signal is high. When pressure is low, the signal is low. The PCM sets the OBDII code when the sensor signal falls outside factory specifications.

P2524 – “A/C” Request “B” Circuit High

P2524 Possible Causes

  • Low refrigerant
  • Excessive refrigerant
  • Faulty low pressure sensor
  • Side low pressure sensor harness is open or shorted
  • Poor electrical connection in low pressure sensor circuit

How to Fix Code P2524

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

Check Engine Light On (or Service Engine Soon Warning Light)

P2524 Meaning

The Powertrain Control Module (PCM) monitors refrigerant pressure through the A/C pressure sensor. The PCM provides a 5V reference and a low reference to the sensor. Changes in A/C refrigerant pressure cause the sensor signal to the PCM to vary. When pressure is high, the signal is high. When pressure is low, the signal is low. The PCM sets the OBDII code when the sensor signal falls outside factory specifications.