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DTC C012F, C12A7, C12DC, or C12DD

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC C012F 00: Brake Boost Solenoid Valve Circuit Malfunction

DTC C12A7 00: ABS Brake Boost Solenoid Valve Circuit Performance

DTC C12DC 00: ABS Brake Boost Solenoid Valve Circuit Malfunction

Circuit/System Description

The brake boost solenoid valve is used to control the amount of brake fluid flow from the high pressure accumulator, which provides brake assist and an improved brake pedal feel. The brake boost solenoid valve is an internal part of the brake pressure modulator.

Conditions for Running the DTC

    • Ignition voltage is greater than 10 V.
    • The Vehicle ON or Vehicle in Service Mode.

Conditions for Setting the DTC

Solenoid feedback current is greater than 25% of commanded current.

Action Taken When the DTC Sets

    • The ABS indicator turns ON.
    • The red brake indicator turns ON.
    • The traction control/stability control indicator turns ON.
    • The Service Brake Assist and Service StabiliTrak messages are displayed on the driver information centre.
    • The electronic brake control module disables the antilock brake system, the traction control system and the electronic stability program for the duration of the drive cycle.

Conditions for Clearing the DTC

    • The condition for setting the DTC is no longer present.
    • The history DTC will clear after 40 consecutive fault-free drive cycles have occurred.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Note: The 12 V battery must be able to maintain a charge during this brake sensor performance procedure. It is recommended that a charger/maintainer or equivalent be used to maintain proper battery voltage during this procedure.

  1. Vehicle in Service Mode with the transmission in PARK.
  2. Note: Do not depress the brake pedal during the Electronic Brake Control Module Learn.

  3. Perform the Electronic Brake Control Module Learn procedure with a scan tool.
  4. Note: To ensure the complete brake modulator and high pressure accumulator pressure relief procedure is allowed to occur; the brake controller must see 1 pedal apply with the propulsion system enabled, followed by a proper shutdown without applying the brake pedal.

  5. Vehicle ON, apply and release the brake pedal.
  6. Note: Vehicle OFF, without applying the brake pedal ensure the brake modulator and high pressure accumulator pressure relief occurs. This process will take approximately 1-3 minutes.

  7. Vehicle OFF, without applying the brake pedal,
  8. Remove the remote keyless entry transmitter and close all of the vehicle doors. Wait approximately 1-3 minutes until the brake modulator and the high pressure accumulator pressure relief is complete and the vehicle powers down.
  9. Vehicle ON, brakes not applied.
  10. Verify the scan tool parameters listed below are within the specified range:
  11. • Brake Controls Brake Pedal Position Sensor 5 V Supply Voltage - Between 4.75-5.25 V.
    • Brake Controls Brake Pedal Position Sensor Circuit 1 - Between 1.4-1.7 V
    • Brake Controls Brake Pedal Position Sensor Circuit 2 - Between 58 78%
    If any parameter is not within the specified range
        Refer to Circuit/System Testing.
    ⇓   If all parameters are within the specified range
  12. Vehicle ON, brakes not applied.
  13. Verify the scan tool parameters listed below are less the specified range:
  14. • Brake Master Cylinder Pressure Sensor - Less than 100 kPa (15 psi)
    • Brake Pressure Sensor - Less than 100 kPa (15 psi)
    • High Pressure Accumulator Sensor - Less than 800 kPa (116 psi)
    If any parameter is greater than the specified range
        Replace the Q5 brake pressure modulator.
    ⇓   If all parameters are less than the specified range
  15. Perform a brake hydraulic system test, refer to Brake Hydraulic and Assist System Diagnosis .
  16. If the brake hydraulic system test does not pass
        Repair as necessary.
    ⇓   If the brake hydraulic system tests normal
  17. Replace the Q5 brake pressure modulator.
  18. Verify the DTC does not set while operating the vehicle under the Conditions for Running the DTC.
  19. If the DTC sets
        K17 electronic brake control module.
    ⇓   If the DTC does not set
  20. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

    •  Electronic Brake Control Module with Brake Pressure Modulator Valve Replacement
    • Control Module References for electronic brake control module replacement, programming and setup
   


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