NO.6 ABS AND BRAKE SYSTEM WARNING LIGHTS COME ON WHEN DRIVING

BME040300000W10

• When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while doing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harness are connected correctly and undamaged.

6

ABS and BRAKE system warning lights come on when driving

[TROUBLESHOOTING HINTS]

• ABS HU/CM initially detects ABS proportioning system malfunction, but detects normal ABS HU/CM operation when ignition switch is turned ON again.

• ABS initially detects low battery voltage, but detects normal ABS HU/CM operation when ignition switch is turned ON again.

Diagnostic procedure

STEP

INSPECTION

ACTION

1
• Perform DTC inspection.
• Is error message displayed regarding communication between ABS HU/CM and WDS or equivalent?
Yes
If a communication error message is displayed even after inspecting according to procedures displayed on the WDS or equivalent, go to Step 4.
No
Go to next step.
2
• Have DTCs been recorded in memory?
Yes
Perform inspection using appropriate DTC.
No
Go to next step.
3
• Inspect the following items using WDS or equivalent.
- ABS_LAMP (ABS warning light)
- BRAKE_LAMP (BRAKE system warning light)
- ABS_VOLT (power supply voltage)
• Drive vehicle under conditions in which warning light illuminates.
• Confirm the voltage for PID/DATA monitor B+ item under the following conditions:
- When ABS warning light and BRAKE system warning light illuminate again
- When ABS_LAMP and/or BRAKE_LAMP is ON

Specification: above more than 10 V

• Is voltage within specification?
Yes
Replace ABS HU/CM (open or ground to short in ABS HU/CM).
No
Go to next step.
4
• Is ABS HU/CM connector securely connected?
Yes
Go to Step 6.
No
Connect ABS HU/CM connector securely, then go to next step.
5
• Drive vehicle under conditions in which warning light illuminates.
• Do both ABS warning light and BRAKE system warning light illuminate again?
Yes
Inspect and repair wiring harness for ABS HU/CM power supply (terminal Z) and ground 1 (terminal AA).
No
Temporary poor connection in connector.
Inspect ABS HU/CM connector and terminal.
*6
• Disconnect ABS HU/CM connector. Connect SST (adapter harness) (vehicle harness side only).
• Is there continuity between SST (adapter harness) connector terminal T and DLC-2?
Yes
Go to next step.
No
Repair wiring harness between ABS HU/CM and DLC-2.
*7
• Is voltage approximately 12 V at SST (adapter harness) connector terminal T?
Yes
Repair wiring harness between ABS HU/CM and DLC-2.
No
Go to next step.
*8
• Is there continuity between SST (adapter harness) connector terminal T and ground?
Yes
Repair wiring harness between ABS HU/CM and DLC-2.
No
Inspect and repair wiring harness for ABS HU/CM power supply (terminal Z) and ground 1 (terminal AA).