Pinpoint Test A: DTC C1300 - ABS Hydraulic Pump Motor Circuit Failure

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Vehicle Dynamic Systems for schematic and connector information.

Normal Operation 

Fused battery voltage is provided to the ABS module from battery junction box (BJB) fuses 109 (20A) and 106 (40A) along circuits 483 (RD) and 601 (LB/PK) respectively. Fused ignition voltage is provided from central junction box (CJB) fuse 13 (10A) along circuit 1003 (GY/YE). When necessary, the ABS module supplies voltage to the hydraulic control unit (HCU) assembly and the pump motor is activated. The ABS module is provided a ground along circuit 57 (BK) and the hydraulic pump motor is provided a ground internally through the HCU.

• DTC C1300 ABS Hydraulic Pump Motor Circuit Failure - When the ignition key is in the RUN position, if the ABS module detects an open circuit, a short to voltage, a short to ground or a seized pump motor, DTC C1300 will be set.

This pinpoint test is intended to diagnose the following:

• Fuse(s)
• Wiring, terminals or connectors
• ABS module
• HCU assembly

PINPOINT TEST A: DTC C1300 - ABS HYDRAULIC PUMP MOTOR CIRCUIT FAILURE 

1. A1 CHECK THE ABS PUMP MOTOR 
   • Key in ON position.
   • Is the ABS pump motor running all the time? 
   1. YES  : INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . TEST the system for normal operation.
   2. NO  : Go to  A2.
2. A2 CHECK THE PUMP MOTOR OUTPUT COMMAND (PMP_MOTOR) 
   • Connect the diagnostic tool.
   • Key in ON position.
   • Enter the following diagnostic mode on the diagnostic tool: ABS DataLogger
   • Toggle the PMP_MOTOR active command ON.
   • Does the ABS pump motor run? 
   1. YES  : TOGGLE the PMP_MOTOR output command OFF.

      CLEAR the DTC. CHECK the yellow ABS warning indicator while driving the vehicle above 12 km/h (7.5 mph). Do not apply the brakes until the vehicle exceeds 32 km/h (20 mph). If the yellow ABS warning indicator illuminates, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . TEST the system for normal operation. If the yellow ABS warning indicator does not illuminate, system is OK. If the yellow ABS warning indicator does illuminate, INSTALL a new HCU. REFER to Hydraulic Control Unit (HCU) .

   2. NO  : TOGGLE the PMP_MOTOR output command OFF. Go to  A3.
3. A3 CHECK THE BJB FUSES 106 (40A) and 109 (20A) 
   • Check fuse: BJB Fuse 106 (40A)
   • Check fuse: BJB Fuse 109 (20A)
   • Are the fuses OK? 
   1. YES  : Go to  A4.
   2. NO  : INSTALL a new fuse(s). TEST the system for normal operation.

      If fuse 106 (40A) fails again, REPAIR circuit 601 (LB/PK). TEST the system for normal operation.

      If fuse 109 (20A) fails again, REPAIR circuit 483 (RD). TEST the system for normal operation.

4. A4 CHECK THE VOLTAGE TO THE ABS MODULE 
   NOTE: To access the ABS module connector, remove the air cleaner assembly.
   • Disconnect: ABS Module C135
   Fig 1: Checking ABS Module Circuit Voltage
   Courtesy of FORD MOTOR CO.
   • Measure the voltage between ground and:
     • ABS module C135-14, circuit 483 (RD), harness side.
     • ABS module C135-13, circuit 601 (LB/PK), harness side
   • Are the voltages greater than 10 volts? 
   1. YES  : Go to  A5.
   2. NO  : REPAIR the affected circuit(s). CLEAR the DTCs. TEST the system for normal operation.
5. A5 CHECK THE ABS MODULE GROUND CIRCUITS FOR AN OPEN 
   Fig 2: Checking Circuits For Open
   Courtesy of FORD MOTOR CO.
   • Measure the resistance between ground and:
     • ABS module C135-12, circuit 57 (BK), harness side.
     • ABS module C135-15, circuit 57 (BK), harness side.
   • Are the resistances less than 5 ohms? 
   1. YES  : Go to  A6.
   2. NO  : REPAIR the affected circuit(s). CLEAR the DTCs. TEST the system for normal operation.
6. A6 CHECK THE PUMP MOTOR FOR CORRECT OPERATION 
   • Disconnect: Pump Motor Connector
   Fig 3: Connecting Jumper Wires
   Courtesy of FORD MOTOR CO.
   • Connect a heavy gauge jumper between the negative battery post and the pump motor connector, brown wire; and momentarily connect a fused (30A) jumper between the positive battery post and the pump motor connector, red wire.
   • Does the pump motor operate? 
   1. YES  : INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . TEST the system for normal operation.
   2. NO  : INSTALL a new HCU. REFER to Hydraulic Control Unit (HCU) . CLEAR the DTCs. TEST the system for normal operation.