NO.5 BOTH ABS WARNING LIGHT AND BRAKE SYSTEM WARNING LIGHT STAY ON MORE THAN 4 S WITH SWITCH THE IGNITION TO ON [ABS]


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5
Both ABS warning light and BRAKE system warning light stay on more than 4 s with switch the ignition to on.
[TROUBLESHOOTING HINTS]
•  ABS HU/CM detects ABS proportioning system malfunction
•  ABS HU/CM detects low voltage in power supply (ABS HU/CM ingestion terminal AF voltage is below about 9 to 10 V)
•  ABS HU/CM does not operate
•  Malfunction of communication network

Diagnostic procedure

STEP

INSPECTION

ACTION

1
CONFIRM INSTRUMENT CLUSTER DTC
•  Retrieve the instrument cluster DTC using the M-MDS.
•  Is DTC U0415:92 retrieved?
Yes
Go to the next step.
No
Go to Step 11.
2
CONFIRM ABS HU/CM DTC
•  Retrieve the ABS HU/CM DTC using the M-MDS.
•  Is any DTC retrieved?
Yes
Perform the applicable DTC troubleshooting procedure.
No
If communication error message is displayed on M-MDS screen, go to the next step.
If communication error message is not displayed, go to Step 7.
3
INSPECT FOR CONNECTION OF ABS HU/CM CONNECTOR
•  Is the ABS connector connected securely?
Yes
Go to the next step.
No
Connect the connector securely, then go to Step 7.
4
INSPECT ABS POWER SUPPLY FUSE
•  Is ABS power supply fuse normal?
Yes
Go to the next step.
No
Inspect for a short to ground on blown fuse’s circuit.
Repair or replace as necessary.
Install appropriate amperage fuse.
*5
VERIFY WHETHER MALFUNCTION IS IN WIRING HARNESS (BETWEEN ABS HU/CM POWER SUPPLY AND ABS HU/CM FOR CONTINUITY) OR ELSEWHERE
•  Switch the ignition to ON.
•  Measure the voltage at ABS HU/CM terminal AF.
•  Is voltage approx. 12 V?
Yes
Go to the next step.
No
Inspect for open circuit between ABS HU/CM and ignition.
Repair or replace as necessary.
*6
VERIFY WHETHER MALFUNCTION IS IN WIRING HARNESS (BETWEEN INSTRUMENT CLUSTER AND GND FOR CONTINUITY) OR ABS HU/CM
•  Switch the ignition to off.
•  Disconnect the instrument cluster.
•  Verify continuity between the harness-side connector terminal A and GND.
•  Is there continuity?
Yes
Replace the ABS HU/CM. (Internal malfunction.)
No
Repair or replace malfunctioning part for open circuit and poor contact in GND point.
7
VERIFY WHETHER MALFUNCTION IS IN ABS HU/CM IGNITION POWER SUPPLY SYSTEM (TERMINAL AF) OR ELSEWHERE
•  Switch the ignition to ON.
•  Monitor ABS HU/CM PID VPWR using the M-MDS.
•  Is the monitored value above 10 V?
Yes
Go to Step 11.
No
Go to the next step.
8
INSPECT BATTERY
•  Is the battery voltage normal?
Yes
Go to the next step.
No
Charge or replace the battery, then go to the next step.
9
INSPECT CHARGING SYSTEM WITH ELECTRICAL LOAD OPERATING
•  Is battery voltage normal with electrical load (A/C, headlight, rear window defroster, etc.) on the engine idling?
Yes
Go to the next step.
No
Inspect the charging system (drive belt tension, generator, etc.).
*10
VERIFY WHETHER MALFUNCTION IS IN WIRING HARNESS (BETWEEN ABS HU/CM POWER SUPPLY AND ABS HU/CM FOR CONTINUITY) OR ELSEWHERE
•  Switch the ignition to ON.
•  Measure the voltage at ABS HU/CM terminal AF.
•  Is voltage above 10 V?
Yes
Replace the ABS HU/CM. (Internal fault.)
No
Inspect for open circuit between ABS HU/CM and ignition.
Repair or replace as necessary.
11
VERIFY WHETHER MALFUNCTION IS IN INSTRUMENT CLUSTER OR ABS HU/CM
•  Turn on and off all warning lights and indicator lights using the instrument cluster PID WL+IL of active command modes using the M-MDS.
•  Does the ABS warning light and brake warning light turn on and off according to simulation status?
Yes
Replace the ABS HU/CM. (Internal fault.)
No
Replace the instrument cluster.

•  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.