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Inspection Procedure 4: The headlights do not illuminate when the passing switch is turned ON.
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
TECHNICAL DESCRIPTION (COMMENT)
If both headlights (low-beam and high-beam) do not illuminate, the passing switch input circuit or ETACS-ECU may have a problem.
 
 
TROUBLESHOOTING HINTS
  • The column switch may be defective
  • The ETACS-ECU may be defective
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
 
 
DIAGNOSIS
STEP 1. Check the operation of the headlights.
Check that the low-beam and high-beam headlights illuminate normally.
Is the check result normal?
Go to Step 2.
Refer to Inspection Procedure 1 "None of the low-beam headlights illuminate ." and Inspection Procedure 2 "None of the high-beam headlights illuminate ."
 
STEP 2. Using scan tool (M.U.T.-IIISE), read the ETACS-ECU DTC.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect Scan Tool (M.U.T.-IIISE) ."
(2) Press the electric motor switch to turn on the power supply mode.
(3) Check whether the ETACS-ECU related DTC is set.
(4) Press the electric motor switch to turn off the power supply mode.
Is the DTC set?
Troubleshoot the ETACS-ECU. Refer to .
Go to Step 3.
 
STEP 3. Retest the system.
Check that the headlights (low-beam and high-beam) illuminates normally when turning ON the passing switch.
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 ETACS-ECU.