STATUS
CODE
DISPLAY MESSAGE RECOVERY METHOD CIRCUIT
8786-4 8786 Automatic LH Traction
Node 4
DESCRIPTION BEHAVIOR
Electric Brake coil short detected - (LH Node 4) Parking brake drops, all truck functions disabled.
Probable Causes and Test Procedures
1. Determine if Electric Brake system at fault:
a. Disconnect the Electric Brake (CPS26), does the fault go away?
YES- Problem is with electric brake system. Proceed to Step 2.
NO- Brake system is not at fault Proceed to Step 5.
2. Check the electric Brake Coil to be between 15 to 20 Ohms?
YES- Brake coil not at fault, proceed to step 3.
NO- Brake coil fault, replace electric brake.
3. Check brake coil connections for short:
a. Measure between Pins 1 and 2 of CPS24 on harness side. Does resistance measure > 1k Ohms?
YES- No harness fault found, controller driver may be at fault, Proceed to step 4.
NO- Locate shorted wires in harness, separate, and repair wires / pin / crimps.
4. Check controller brake coil driver for short:
a. Disconnect CPS42 and measure between Pin 4 of traction controller and B−. Does resistance
measure < 1k Ohms?
YES- Controller at fault, contact Service Engineering.
NO- No cause found, contact Service Engineering.
5. Check other coil fault codes before troubleshooting (multiple outputs monitored simultaneously for this
fault).
Troubleshooting 2200 YRM 1415
28
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