Inspection Procedure O-3

The key reminder switch signal Is not sent to the ETACS-ECU.

Key Reminder Switch Input Circuit:

Connectors:

CIRCUIT OPERATION
The ETACS-ECU operates various functions according to the input signal from the key reminder switch.

TECHNICAL DESCRIPTION (COMMENT)
The key reminder switch input signal is used to operate the following functions or system:
- Ignition key reminder tone alarm function
- Forgotten key prevention function
- Keyless entry system
- Interior lights dimming function
- Theft-alarm system

If the signal fails, these functions or system will not work normally.

TROUBLESHOOTING HINTS
- Malfunction of the key reminder switch
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991529: Diagnostic Trouble Code Check Harness







STEP 1. Check the key reminder switch.
Disconnect key reminder switch connector C-201. Then check the continuity.

Q: Is the key reminder switch in good condition?

YES: Go to Step 2.
NO: Repair it. The key reminder switch input signal should be able to be checked and the functions, which are described in the "Technical Description (comment)," should work normally.

STEP 2. Check the key reminder switch ground circuit at the key reminder switch connector C-201.
1. Disconnect the key reminder switch connector C-201 and measure at the harness side.




2. Measure the resistance between terminal 4 and ground.

Q: Is the resistance less than 2 ohm?

YES: Go to Step 5.
NO: Go to Step 3.




STEP 3. Check key reminder switch connector C-201 for damage.

Q: Is key reminder switch connector C-201 in good condition?

YES: Go to Step 4.
NO: Repair or replace it. Refer to Harness Connector Inspection. The key reminder switch input signal should be able to be checked and the functions, which are described in the "Technical Description (comment)," should work normally.




STEP 4. Check the harness wire between key reminder switch connector C-201 and ground.

Q: Is the harness wires between key reminder switch connector C-201 and ground in good condition?

YES: There is no action to be taken.
NO: Repair them. The key reminder switch input signal should be able to be checked and the functions, which are described in the "Technical Description (comment)," should work normally.







STEP 5. Check key reminder switch connector C-201 and ETACS-ECU connector C-313 for damage.

Q: Are key reminder switch connector C-201 and ETACS-ECU connector C-313 in good condition?

YES: Go to Step 6.
NO: Repair or replace them. Refer to Harness Connector Inspection. The key reminder switch input signal should be able to be checked and the functions, which are described in the "Technical Description (comment)," should work normally.







STEP 6. Check the harness wire between key reminder switch connector C-201 and ETACS-ECU connector C-313.

Q: Is the harness wire between key reminder switch connector C-201 and ETACS-ECU connector C-313 in good condition?

YES: Replace the ETACS-ECU. The key reminder switch input signal should be able to be checked and the functions, which are described in the "Technical Description (comment)," should work normally.
NO: Repair it. The key reminder switch input signal should be able to be checked and the functions, which are described in the "Technical Description (comment)," should work normally.