NO.5 ABS WARNING LIGHT STAYS ON 4 S OR MORE WHEN IGNITION SWITCH TURNED TO ON POSITION [ABS]

id0403a5810200

5 | ABS warning light stays on 4 s or more when ignition switch turned to ON position
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POSSIBLE CAUSE | • ABS HU/CM DTC is stored • ABS HU/CM malfunction (open or short to ground in ABS HU/CM internal circuit) • Open circuit in wiring harness between ABS HU/CM terminal Y, Z and DLC-2 • Short to power supply in wiring harness between ABS HU/CM terminal D and body ground • Short to ground in wiring harness between ABS HU/CM terminal D and body ground • ABS HU/CM malfunction (ABS HU/CM internal communication circuit malfunction)

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC‐2 FOR CONTINUITY AND SHORTS • Perform the Reading DTCs Procedure. (See ON-BOARD DIAGNOSIS [ABS].) • Is the 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 4.
No | Go to the next step.
2 | CONFIRM ABS HU/CM DTC • Perform the Reading DTCs Procedure. (See ON-BOARD DIAGNOSIS [ABS].) • Are any DTC present? | Yes | Go to the applicable DTC inspection. (See ON-BOARD DIAGNOSIS [ABS].)
No | Go to the next step.
3 | INSPECT WARNING LIGHT OPERATION • Turn on the all warning light on instrument cluster using the instrument cluster input/output check code 26. (See INSTRUMENT CLUSTER INPUT/OUTPUT CHECK MODE.) • Do the ABS and brake system warning light illuminate? | Yes | Replace the ABS HU/CM (open or short to ground in ABS HU/CM internal circuit). (See ABS HU/CM REMOVAL/INSTALLATION.)
No | Replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
*4 | INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC‐2 FOR CONTINUITY • Turn the ignition switch off. • Inspect for continuity between ABS HU/CM terminal Y, Z and DLC-2 (wiring harness-side). • Is there continuity? | Yes | Go to the next step.
No | Repair or replace the wiring harness for a possible open circuit.
*5 | INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC‐2 FOR SHORT TO POWER SUPPLY • Turn the ignition switch to the ON position (engine off). • Measure the voltage at ABS HU/CM terminal Y, Z (wiring harness-side). • Is the voltage approx. 12 V? | Yes | Repair or replace the wiring harness for a possible short to power supply.
No | Go to the next step.
*6 | INSPECT WIRING HARNESS BETWEEN ABS HU/CM AND DLC‐2 FOR SHORT TO GROUND • Turn the ignition switch off. • Inspect for continuity between ABS HU/CM terminal Y, Z (wiring harness-side) and body ground. • Is there continuity? | Yes | Repair or replace the wiring harness for a possible short to ground.
No | Replace the ABS HU/CM (ABS HU/CM internal communication circuit malfunction). (See ABS HU/CM REMOVAL/INSTALLATION.)

• 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.