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Inspection Procedure 10: The hazard warning light switch signal is not received.
 
 
caution
  • Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
TECHNICAL DESCRIPTION (COMMENT)
The hazard warning light switch input signal is used for the operation judgment of hazard warning light. Therefore, if the signal is abnormal, the hazard warning light will not illuminate.
 
 
TROUBLESHOOTING HINTS
  • The hazard indicator assembly 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
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Check the hazard indicator assembly.
Refer to .
Is the check result normal?
Go to Step 2.
Replace the hazard indicator assembly.
 
STEP 2. Resistance measurement at hazard indicator assembly connector (ground terminal).
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between the hazard indicator assembly connector (ground terminal) and body ground.
OK: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 4.
Go to Step 3.
 
STEP 3. Check of open circuit in ground line between hazard indicator assembly connector and body ground.
Is the check result normal?
Intermittent malfunction is suspected (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 4. Check of short to power supply, short to ground, and open circuit in HAZ line between ETACS-ECU connector and hazard indicator assembly connector.
Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.
 
STEP 5. Using scan tool (M.U.T.-IIISE), check data list.
Check the ETACS-ECU data list.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position 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) Check the input signals from the hazard warning light switch.
  • Turn ON the hazard warning light switch.
 
Item No.Item nameNormal condition
89Hazard switchON
Item No.Item nameNormal condition
89Hazard switchON
OK: Normal condition is displayed.
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.