Pinpoint Test I: DTC C1285- Booster Solenoid Circuit Failure

• Key in ON position.
• Enter the following diagnostic mode on the diagnostic tool: Clear DTC.
• Carry out the active brake booster recalibration procedure using the diagnostic tool.
• Enter the following diagnostic mode on the diagnostic tool: Retrieve DTCs.
• Are any DTCs retrieved or does the recalibration procedure indicate a fault? 

Yes 

If DTC C1285 is retrieved, or the brake booster portion of the recalibration procedure indicates a failure, GO to I2.

If any other DTC is retrieved, GO to the ANTI-LOCK BRAKE SYSTEM (ABS) MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX .

No 

The ABS system is operating correctly.

• Key in OFF position.
• Disconnect: Active Brake Booster C149.
• Measure the resistance between the active brake booster C149-3, circuit 1583 (BN/WH), component side and the active brake booster C149-4, circuit 1582 (LG/RD), component side.
  Fig 1: Measuring Resistance Between Active Brake Booster C149-3, Circuit 1583 (BN/WH)

  Courtesy of FORD MOTOR CO.
• Is the resistance between 1 and 2 ohms? 

Yes 

GO to I3.

No 

INSTALL a new active brake booster. REFER to BRAKE SYSTEM-GENERAL INFORMATION . CLEAR the DTCs. RECALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REPEAT the self-test.

• Key in OFF position.
• Disconnect: ABS Module C155.
• Measure the resistance between the ABS module C155-17, circuit 1582 (LG/RD), harness side and the active brake booster C149-4, circuit 1582 (LG/RD), harness side; and between the ABS module C155-31, circuit 1583 (BN/WH), harness side and the active brake booster C149-3, circuit 1583 (BN/WH).
  Fig 2: Measuring Resistance Between ABS Module C155-17, Circuit 1582 (LG/RD)

  Courtesy of FORD MOTOR CO.
• Are the resistances less than 5 ohms? 

Yes 

GO to I4.

No 

REPAIR the circuit(s) in question. CLEAR the DTCs. RECALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REPEAT the self-test.

• Measure the resistance between the active brake booster C149-4, circuit 1582 (LG/RD), harness side and ground; and between the active brake booster C149-3 circuit 1583 (BN/WH), harness side and ground.
  Fig 3: Measuring Resistance Between Active Brake Booster C149-4, Circuit 1582 (LG/RD)

  Courtesy of FORD MOTOR CO.
• Are the resistances greater than 10,000 ohms? 

Yes 

GO to I5.

No 

REPAIR the circuit(s) in question. CLEAR the DTCs. RECALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REPEAT the self-test.

• Key in ON position.
• Measure the voltage between the active brake booster C149-4, circuit 1582 (LG/RD), harness side and ground; and between the active brake booster C149-3 circuit 1583 (BN/WH), harness side and ground.
  Fig 4: Measuring Voltage Between Active Brake Booster C149-4, Circuit 1582 (LG/RD)

  Courtesy of FORD MOTOR CO.
• Is any voltage present? 

Yes 

REPAIR the circuit(s) in question. CLEAR the DTCs. RECALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REPEAT the self-test.

No 

GO to I6.

• Key in OFF position.
• Connect: Active Brake Booster C149.
• Connect: ABS Module C155.
• Key in ON position.
• Start the engine and wait approximately one minute to create vacuum in the brake booster and then place the ignition switch in the OFF position.
• Disconnect: ABS Module C155.
• Connect a fused (10A) jumper wire between the ABS module C155-31, circuit 1583 (BN/WH), harness side and ground.
  Fig 5: Connecting Fused (10A) Jumper Wire Between ABS Module C155-31, Circuit 1583 (BN/WH)

  Courtesy of FORD MOTOR CO.
• While observing the brake pedal for movement, connect a fused (10A) jumper wire for approximately two seconds between the ABS module C155-17, circuit 1582 (LG/RD), harness side and the positive battery post.
  Fig 6: connecting Fused (10A) Jumper Wire For Approximately Two Seconds Between ABS Module C155-17, Circuit 1582 (LG/RD)

  Courtesy of FORD MOTOR CO.
• Does the brake pedal move? 

Yes 

GO to I7.

No 

INSTALL a new active brake booster. REFER to BRAKE SYSTEM-GENERAL INFORMATION . CLEAR the DTCs. RECALIBRATE the ABS module. REPEAT the self-test.

• Disconnect all ABS connectors.
• Check for:
  • corrosion
  • pushed-out pins
• Connect all ABS connectors and make sure they seat correctly.
• Operate the system and verify the concern is still present.
• Is the concern still present? 

Yes 

INSTALL a new ABS module. refer to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE . TEST the system for normal operation.

No 

The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.