C0285 GMC - Medium Pressure Accumulator Switch Remains Open

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3   
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C0285 GMC Possible Causes

  • Faulty Brake Pressure Modulator Valve (BPMV)
  • Brake Pressure Modulator Valve (BPMV) harness is open or shorted
  • Brake Pressure Modulator Valve (BPMV) circuit poor electrical connection

First diagnose C0285 GMC 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 terminals.

Cost of diagnosing the C0285 GMC code

    Labor: 1.0

    The cost of diagnosing the C0285 GMC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle's make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

C0285 GMC Possible Symptoms

  • Anti-Lock Brake System (ABS) Warning Light ON
  • Engine Light ON (or Service Engine Soon Warning Light)

C0285 Gmc Description

The Brake Pressure Modulator Valve (BPMV) contains a Medium Pressure Accumulator (MPA). The MPA provides pressure to the front brakes during certain VSES events. The MPA switch is included to monitor the status of the pressure accumulator. The MPA switch is open when the MPA is uncharged.

The integrity of the MPA switch is tested by the Electronic Brake Control Module (EBCM). The MPA is partially discharged during system initialization to open the switch and then recharged to close the switch. The EBCM continues to monitor the switch to ensure the MPA remains charged. Provided the VSES is not activated, the MPA should remain charged for the entire ignition cycle. If the MPA switch opens within 5 minutes of closing, a fast leak down condition is detected. If the MPA switch opens after 5 minutes has passed, a slow leak down condition is detected.

OBDII Code C0285 Gmc - Medium Pressure Accumulator Switch Remains Open - AutoCodes.com

C0285 GMC More Information

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