NO.7 ABS WARNING LIGHT COMES ON WHEN DRIVING

BME040300000W11

• 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.

7

ABS warning light comes on when driving

[TROUBLESHOOTING HINTS]

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

• ABS initially detects low battery voltage (ABS HU/CM terminal Z voltage is below about 10 V and above about 8.5 V), 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 7.
No
Go to next step.
2
• Have DTCs been recorded in memory?
Yes
Perform inspection using appropriate DTC.
No
Go to next step.
3
• Select the following items using WDS or equivalent.
- ABS_LAMP (ABS warning light)
- ABS_VOLT (power supply voltage)
• Drive vehicle under conditions in which warning light illuminates.
• Does ABS_LAMP go ON when ABS warning light illuminates again?
Yes
Go to Step 6.
No
Go to next step.
*4
• Disconnect ABS HU/CM connector. Connect SST (adapter harness) (vehicle harness side only).
• Use the SST (adapter harness) connector to ground ABS warning light terminal W to body ground.
• Drive vehicle under conditions in which warning light illuminates.
• Does ABS warning light go out?
Yes
Replace ABS HU/CM (open circuit in ABS HU/CM).
No
Go to next step.
*5
• Is there continuity between following SST (adapter harness) connector terminal W and instrument cluster connector (16-pin) terminal 1B?
Yes
Replace instrument cluster (open or ground to short in instrument cluster).
No
Repair wiring harness between ABS HU/CM (terminal W) and instrument cluster (terminal 2B).
6
• Check the voltage for PID/DATA monitor ABS_VOLT item when ABS warning light illuminates again.

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.
7
• Is battery voltage normal?
Yes
Go to next step.
No
Perform inspection of battery and charging system.
8
• Is battery voltage normal with electrical load (A/C, headlights, etc.) on while engine is idling?
Yes
Go to next step.
No
Perform inspection of charging system (drive belt tension, generator, etc.).
9
• Is ABS HU/CM connector terminal W securely connected?
Yes
Go to Step 11.
No
Connect ABS HU/CM connector terminal W securely, then go to next step.
10
• Drive vehicle under conditions in which warning light illuminates.
• Does ABS 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 of terminal.
Inspect ABS HU/CM connector and terminal.
*11
• 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.
*12
• 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.
*13
• 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).