Inspection Procedure 6: 4WD indicator lamp does not illuminate.
<Vehicles with 4WD and 5M/T>
| caution |
Before replacing the combination meter, be
sure to check that the power supply circuit, earth circuit,
and communication circuit are normal.
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COMMENTS ON TROUBLE SYMPTOM
- When the signal from each ECU is received via the CAN
communication, the combination meter (2WD/4WD operation
indicator lamp and 4L indicator lamp) illuminates the
corresponding display lamp.
If the lamps do not illuminate
normally, the wiring harness and connector(s) in the CAN bus
lines, each ECU (that sends a signal) or the combination meter
may have a problem.
- If the combination meter (centre differential lock lamp) do not
illuminate normally, the 4WD indicator-ECU, input circuit, or
the combination meter may be defective.
PROBABLE CAUSES
- Malfunction of the 4WD indicator-ECU
- Malfunction of the combination meter
- Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
STEP 1. Retest the system.
Check the 4WD
indicator lamp lamps are illuminate normally.
Q.
Is the check result normal?
The trouble can be an
intermittent malfunction (Refer to GROUP 00 - How to use
Troubleshooting/inspection Service Points - How to Cope with
Intermittent Malfunction).
NO <2WD/4WD operation indicator
lamp or 4L indicator lamp>
: Go to Step
2.
NO <Centre differential lock lamp> : Go to
Step 4.
STEP 2. M.U.T.-III CAN bus
diagnostics
Use the M.U.T.-III to diagnose the CAN bus
lines.
Q.
Is the check result normal?
Go to Step
3.
Repair the CAN bus
line (Refer to GROUP 54C - Troubleshooting 
).
STEP 3. Check the other system
troubleshooting
Refer to GROUP 54C - Gateway, Input
signal check
Q.
Is the check result normal?
Go to Step
6.
Refer to GROUP 54C
- Gateway, Input signal check .
STEP 4. Voltage measurement at the 4WD
indicator-ECU connector
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(1)Disconnect the connector, and measure at the
wiring harness side.
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(2)Turn the ignition switch to the "ON"
position.
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(3)Measure the voltage between the 4WD indicator-ECU
connector (C/DI terminal) and the body earth.
OK:
System voltage
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Q.
Is the check result normal?
Go to Step 6.
Go to Step
5.
STEP 5. Check of short, open circuit in
body earth line between 4WD indicator-ECU connector or combination
meter connector.
Q.
Is the check result normal?
The trouble can be an
intermittent malfunction (Refer to GROUP 00 - How to use
Troubleshooting/inspection Service Points - How to Cope with
Intermittent Malfunction).
Repair the connector(s) or
wiring harness.
STEP 6. Check the 4WD
indicator-ECU.
- Refer to GROUP 22A - 4WD indicator-ECU, Inspection .
Q.
Is the check result normal?
Go to Step
7.
Replace the each
switch on transfer assembly or 4WD indicator-ECU.
STEP 7. Retest the system.
Check the 4WD
indicator lamps are illuminate normally.
Q.
Is the check result normal?
The trouble can be an
intermittent malfunction (Refer to GROUP 00 - How to use
Troubleshooting/inspection Service Points - How to Cope with
Intermittent Malfunction).
Replace the combination
meter.