C1300
Anti-Lock Control
Pinpoint Test C: DTC C1300
Normal Operation
The operating voltage required to run the hydraulic pump motor is between 10 and 17 volts. Fused battery voltage for the hydraulic pump motor is supplied to the ABS module from the Battery Junction Box (BJB). The hydraulic pump motor is internal to the Hydraulic Control Unit (HCU). If a new hydraulic pump motor is needed, a new HCU (Hydraulic Control Unit) must be installed.
- DTC C1300 (ABS Pump Motor Circuit Failure)- this DTC sets every ignition cycle or in on-demand memory if there are circuit failures such as a short to ground, open, high circuit resistance, damaged motor, blown fuse. 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. DTC C1300 sets if this fault is detected 3 times. DTCs set in the ignition cycle can only be cleared by cycling the ignition off and on once the fault has been corrected.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- HCU (Hydraulic Control Unit)
- ABS module
PINPOINT TEST C : DTC C1300
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
C1 CHECK THE ABS PUMP MOTOR
- Ignition ON.
Is the ABS pump motor running all the time?
Yes
INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . TEST the system for normal operation.
No
GO to C2.
C2 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 C5.
If the yellow ABS warning indicator does not illuminate, the system is OK.
No
TOGGLE the PMP_MOTOR output command OFF. GO to C3.
C3 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 C4.
No
VERIFY BJB (Battery Junction Box) fuse 47 (60A) is OK. If OK, REPAIR open in circuit SBB47 (WH/RD). If not OK, REPAIR the short circuit in circuit SBB47 (WH/RD). CLEAR the DTCs. REPEAT the self-test.
C4 CHECK THE ABS MODULE GROUND CIRCUIT FOR AN OPEN OR EXCESSIVE RESISTANCE
- Ignition OFF.
- Disconnect: Battery Negative Cable.
- 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 C5.
No
REPAIR circuit GD121 (BK/YE). CLEAR the DTCs. REPEAT the self-test.
C5 CHECK THE ABS MODULE POWER CIRCUIT FOR CONTINUITY
- Measure the resistance between the ABS module C135-1, circuit SBB47 (WH-RD), harness side and battery positive.
Is the resistance less than 0.5 ohms?
Yes
GO to C6.
No
REPAIR the open circuit SBB47 (WH/RD). CLEAR the DTCs. REPEAT the self-test.
C6 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect: ABS Module C135.
- Check the connector for:
- corrosion
- damaged pins
- pushed-out pins
- Connect: ABS Module C135.
- Connect: Battery Negative Cable.
- 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 HCU (Hydraulic Control Unit). REFER to Hydraulic Control Unit (HCU) . 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.