Pinpoint Test B: DTC C1300
Anti-Lock Control
Pinpoint Tests
Pinpoint Test B: DTC C1300
Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number
Normal Operation
The operating voltage required to run the hydraulic pump motor is between 10 and 16 volts. Fused battery voltage for the hydraulic pump motor is supplied to the ABS module from Battery Junction Box (BJB) fuse 47 (60A) along circuit SBB47 (WH/RD). Ground is provided along circuit GD121 (BK/YE). The hydraulic pump motor is internal to the Hydraulic Control Unit (HCU). If a new hydraulic pump motor is needed, a new HCU must be installed.
- DTC C1300 (ABS Pump Motor Circuit Failure) - The ABS module continuously checks the pump motor electrical circuits. If there is a circuit failure such as a short to ground, DTC C1300 will be set. The module also checks the motor after every actuation. When the pump is shut off, the ABS module measures the output voltage of the motor. If the voltage drops too quickly, there may be a locked motor. If this is detected 3 times, DTC C1300 will be set.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- HCU
- ABS module
PINPOINT TEST B: DTC C1300
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
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B1 CHECK THE ABS PUMP MOTOR
- Ignition ON.
- Is the ABS pump motor running all the time?
Yes
GO to B5.
No
GO to B2.
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B2 CHECK THE ABS MODULE PUMP MOTOR (PMP_MOTOR) OUTPUT COMMAND
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS Module .
- Toggle the PMP_MOTOR output command ON.
- Does the ABS pump motor run for approximately 3 seconds?
Yes
TOGGLE the PMP_MOTOR output command OFF.
CLEAR the DTCs. CHECK the yellow ABS warning indicator while driving the vehicle (the brakes must not be applied) above 32 km/h (20 mph).
If the yellow ABS warning indicator illuminates, RETRIEVE the DTCs. If DTC C1300 is retrieved again, GO to B5.
If the yellow ABS warning indicator does not illuminate, the system is OK.
No
TOGGLE the PMP_MOTOR output command OFF. GO to B3.
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B3 CHECK FOR VOLTAGE TO THE ABS MODULE
- Ignition OFF.
- Disconnect: ABS Module C135 .
- Ignition ON.
- Measure the voltage between ABS module C135-1, circuit SBB47 (WH/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to B4.
No
VERIFY BJB fuse 47 (60A) is OK. If OK, REPAIR circuit SBB47 (WH/RD). CLEAR the DTCs. REPEAT the self-test.
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B4 CHECK THE ABS MODULE GROUND CIRCUIT FOR AN OPEN OR EXCESSIVE RESISTANCE
- Ignition OFF.
- Measure the resistance between ABS module C135-13, circuit GD121 (BK/YE), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to B5.
No
REPAIR circuit GD121 (BK/YE). CLEAR the DTCs. REPEAT the self-test.
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B5 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect: ABS Module C135 .
- Check the connector for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: ABS Module C135 .
- Make sure the connector seats correctly, then 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 Service and Repair. TEST the system for normal operation.
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.
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