NO.1 ABS WARNING LIGHT STAYS ON MORE THAN 4 SECONDS WITH IGNITION SWITCH ON.


BME040367650W01

1

ABS warning light stays on more than 4 seconds with ignition switch ON.

[TROUBLESHOOTING HINTS]

• ABS/TCS HU/CM detects ABS system malfunction.

• ABS/TCS HU/CM detects low voltage in power supply. (ABS/TCS HU/CM Terminal Z voltage is below about 10 V)

• ABS/TCS HU/CM does not operate.

• ABS warning light circuit open or shorted to ground.

Diagnostic procedure

STEP

INSPECTION

ACTION

1
INSPECT ABS (ABS/TCS) HU/CM IGNITION POWER SUPPLY FUSE
• Is ABS (ABS/TCS) HU/CM ignition power supply fuse okay?
Yes
Go to next step.
No
Check for a short to ground on blown fuse's circuit.
Repair or replace as necessary.
Install appropriate amperage fuse.
2
INSPECT WIRING HARNESS BETWEEN ABS (ABS/TCS) HU/CM AND DLC (DATA KINK CONNECTOR-2) FOR CONTINUITY AND SHORTS
• Perform DTC inspection.
• Is error message displayed regarding communication between ABS (ABS/TCS) 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 8.
No
Go to next step.
3
CHECK FOR DTCs IN ABS (ABS/TCS) HU/CM
• Have DTCs been recorded in memory?
Yes
Perform inspection using appropriate DTC.
No
Go to next step.
4
INSPECT PID/DATA IN ABS (ABS/TCS) HU/CM
• Inspect the following items using WDS or equivalent.
- ABS_LAMP (ABS warning light)
- ABS_VOLT (power supply voltage)
• Is ABS_LAMP ON after more than 4 seconds with ignition switch ON?
Yes
Go to Step 7.
No
Go to next step.
5*
CHECK FOR OPEN CIRCUITS IN ABS (ABS/TCS) HU/CM
• Disconnect ABS (ABS/TCS) HU/CM. Connect SST (harness adapter) (vehicle harness side only).
• Use the SST (adapter harness) connector to ground ABS warning light Terminal W to body ground.
• Does ABS warning light go out with ignition switch ON?
Yes
Replace ABS (ABS/TCS) HU/CM (open circuit in ABS (ABS/TCS) HU/CM).
No
Go to next step.
*6
INSPECT WIRING HARNESS BETWEEN ABS (ABS/TCS) HU/CM AND INSTRUMENT CLUSTER FOR CONTINUITY
• Disconnect all instrument cluster.
• Is there continuity between SST (adapter harness) connector terminal W and instrument cluster connector (16-pin) terminal 1B?
Yes
Replace instrument cluster (open or short to ground in instrument cluster).
No
Inspect wiring harness between ABS (ABS/TCS) HU/CM (Terminal W) and instrument cluster.
7
INSPECT ABS (ABS/TCS) HU/CM IGNITION POWER SUPPLY SYSTEM (TERMINAL Z)
• Check the voltage for PID/DATA monitor ABS_VOLT item.

Specification: above 10 V

• Is voltage within specification?
Yes
Replace ABS (ABS/TCS) HU/CM (open or short circuit to B+ in ABS (ABS/TCS) HU/CM).
No
Go to next step.
8
INSPECT BATTERY
• Is battery voltage normal?
Yes
Go to next step.
No
Perform inspection of battery and charging system.
9
INSPECT CHARGING SYSTEM
• 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.).
10
VERIFY THAT ABS (ABS/TCS) HU/CM IS CONNECTED
• Is ABS (ABS/TCS) HU/CM connector securely connected?
Yes
Go to Step 12.
No
Connect ABS (ABS/TCS) HU/CM securely, then go to next step.
11
VERIFY THAT MALFUNCTION SYMPTOM OCCURS AFTER ABS (ABS/TCS) HU/CM IS CONNECTED
• Does ABS warning light go out after more than 4 seconds with ignition switch ON?
Yes
Temporary poor connection in ABS (ABS/TCS) HU/CM connector.
Inspect connector and terminal.
No
Go to next step.
*12
VERIFY THAT ABS HU/CM CONNECTOR TERMINALS Z, AA AND W ARE CONNECTED
• Does malfunction symptom happen again when ABS HU/CM connector Terminals Z, AA and W are shaken while the ignition switch is ON?
Yes
Connect ABS HU/CM connector Terminals Z, AA and W securely, then go to next step.
No
Go to Step 14.
13
VERIFY THAT MALFUNCTION SYMPTOM OCCURS AFTER ABS HU/CM CONNECTOR TERMINALS Z, AA AND W ARE CONNECTED
• Does ABS warning light go out after more than 4 seconds with ignition switch ON?
Yes
Temporary poor connection at terminal.
Inspect ABS HU/CM connector and terminal.
No
Go to next step.
*14
INSPECT WIRING HARNESS BETWEEN FUSE BLOCK AND ABS HU/CM (TERMINAL Z) FOR CONTINUITY
• Disconnect ABS HU/CM. Connect SST (adapter harness) (vehicle harness side only).
• Is voltage approximately 12 V at SST (adapter harness) connector Terminal Z?
Yes
Go to next step.
No
Repair wiring harness between fuse block and ABS HU/CM.
*15
INSPECT WIRING HARNESS BETWEEN ABS HU/CM (TERMINAL AA) AND GROUND FOR CONTINUITY
• Turn ignition switch to OFF.
• Is there continuity between SST (adapter harness) connector Terminal AA and ground?
Yes
If a communication error message is displayed on WDS or equivalent in Step 2 inspection, go to next step.
If a communication error message is not displayed on WDS or equivalent in Step 2 inspection, recheck malfunction symptoms.
No
Repair wiring harness between ABS HU/CM and ground.
*16
INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC-2 (DATA KINK CONNECTOR-2) FOR CONTINUITY
• 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.
*17
INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC-2 (DATA KINK CONNECTOR-2) FOR SHORT TO B+
• 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.
*18
INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC-2 (DATA KINK CONNECTOR-2) FOR SHORT TO GROUND
• Is there continuity between SST (adapter harness) connector Terminal T and ground?
Yes
Repair wiring harness between ABS HU/CM and DLC-2 .
No
Replace ABS HU/CM (communication circuit malfunction in ABS HU/CM).