Pinpoint Test E: DTC C1266 Anti-lock Brake System (ABS) Power Valve Relay Circuit Failure: Testing

WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

E1 CHECK CIRCUIT 685 (BK/WH) FOR VOLTAGE
- Key in OFF position.
- Disconnect: ABS Module C135.
- Measure the voltage between the ABS module C135-25, circuit 685 (BK/WH), harness side and ground.
  
  Fig 1: Checking Circuit 685 (BK/WH) For Voltage
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to E2.
- No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
E2 CHECK CIRCUIT 1203 (BK/LB) FOR GROUND
- Key in OFF position.
- Measure the resistance between the ABS module C135-38, circuit 1203 (BK/LB), harness side and ground.
  
  Fig 2: Checking Circuit 1203 (BK/LB) For Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to E3.
- No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
E3 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect the ABS module connector.
- Check for:
  - corrosion
  - pushed-out pins
- Connect the ABS module connector and make sure it seats 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 . CLEAR the DTCs. REPEAT the self-test.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.