NO.4 BOTH ABS WARNING LIGHT AND BRAKE SYSTEM WARNING LIGHT STAY ON 4 S OR MORE WHEN IGNITION SWITCH TURNED TO ON POSITION

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4

Both ABS warning light and BRAKE system warning light stay on 4 s or more when the ignition switch is turned to the ON position.

[TROUBLESHOOTING HINTS]

• ABS HU/CM detects ABS proportioning system malfunction.

• ABS HU/CM detects low voltage in power supply (ABS CM ignition terminal J voltage is below about 9 to 10 V).

• ABS HU/CM does not operate.

• Malfunction of communication network.

Diagnostic procedure

STEP

INSPECTION

ACTION

1
INSPECT ABS HU/CM POWER SUPPLY FUSE
• Is the ABS HU/CM ignition power supply fuse normal?
Yes
Go to the next step.
No
Inspect for a short to ground on circuit with the blown fuse.
Repair or replace if necessary.
Install appropriate amperage fuse.
2
INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC-2 FOR CONTINUITY AND SHORTS
• Perform DTC inspection.
• Is error message displayed regarding communication between ABS HU/CM and M-MDS?
Yes
If a communication error message is displayed even after inspecting according to the procedure displayed on the M-MDS, go to step 10.
No
Go to the next step.
3
INSPECT FOR DTCS IN ABS HU/CM
• Have DTCs been stored in memory?
Yes
Perform the applicable DTC inspection.
(See DTC Table.)
No
Go to the next step.
4
INSPECT WARNING LIGHT OPERATION
• Turn on the all warning light on instrument cluster using the instrument cluster input/output check code26.
• Do the ABS and BRAKE system warning light illuminate?
Yes
Go to the next step.
No
Replace the instrument cluster.
5
INSPECT ABS HU/CM IGNITION POWER SUPPLY SYSTEM (TERMINAL J)
• Inspect the voltage for datalogger ABS_VOLT item using the M-MDS.

Specification: approx. 10 V

• Is the voltage within specification?
Yes
Replace the ABS HU/CM (open or short in ground circuit in ABS HU/CM).
No
Go to the next step.
6
INSPECT BATTERY
• Is the battery voltage normal?
Yes
Go to the next step.
No
Inspect the battery and charging system.
7
INSPECT CHARGING SYSTEM
• Is the battery voltage normal with the electrical load (A/C, headlight, etc.) on and the engine idling?
Yes
Go to the next step.
No
Inspect the charging system (drive belt tension, generator, etc.).

*8

INSPECT WIRING HARNESS BETWEEN ABS HU/CM POWER SUPPLY AND ABS HU/CM FOR CONTINUITY
• Disconnect the ABS HU/CM connector.
• Is the voltage approx. 12 V at connector terminal Z?
Yes
Go to the next step.
No
Inspect the ABS HU/CM connector for secure connection.

*9

INSPECT WIRING HARNESS BETWEEN ABS HU/CM GROUND FOR CONTINUITY
• Turn the ignition switch to the LOCK position.
• Is there continuity between connector terminal D and the ground?
Yes
If a malfunction error message is displayed on the M-MDS in Step 1 inspection, go to the next step.
If a malfunction error message is not displayed on the M-MDS in Step 1 inspection, troubleshooting is completed.
No
Repair the wiring harness between ABS HU/CM and ground.

*10

INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC-2 FOR CONTINUITY
• Is there continuity between connector terminal Z, Y and DLC-2?
Yes
Go to the next step.
No
Repair the wiring harness between ABS HU/CM and DLC-2.

*11

INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC-2 FOR SHORT TO BATTERY
• Is the voltage approx. 12 V at connector terminal Z, Y?
Yes
Repair the wiring harness between ABS HU/CM and DLC-2.
No
Go to the next step.

*12

INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC-2 FOR SHORT TO GROUND
• Is there continuity between connector terminal Z, Y and DLC-2?
Yes
Repair the wiring harness between ABS HU/CM and DLC-2.
No
Replace the ABS HU/CM (communication circuit malfunction in ABS HU/CM).

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