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Inspection Procedure 3: The key reminder switch signal is not received. <Vehicles without KOS>
 
 
caution
  • Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
  • When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)
 
 
TECHNICAL DESCRIPTION (COMMENT)
The key reminder switch input signal is used for the operation judgment of the functions below. If the signal is abnormal, these functions will not work.
  • Ignition key reminder function
  • Central door locking
  • Keyless entry system
  • Ignition key cylinder illumination light
  • Dome light
 
 
TROUBLESHOOTING HINTS
  • The key reminder 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
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Check the key reminder switch.
Refer to .
Is the check result normal?
Go to Step 2.
Replace the key reminder switch.
 
STEP 2. Resistance measurement at key reminder switch connector (ground terminal)
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between the key reminder switch connector (ground terminal) and 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 key reminder switch connector and the 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 HL1+ line between ETACS-ECU connector and key reminder switch 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.-III), check data list.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect Scan Tool (M.U.T.-III) ."
(2) Check the input signals from the key reminder switch.
  • Ignition switch: "LOCK" (OFF) (key inserted)
 
Item No.Item nameNormal condition
264Handle lock switchKey in
Item No.Item nameNormal condition
264Handle lock switchKey in
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.