Inspection Procedure O-1

The ETACS-ECU does not receive any signal from the key reminder switch.

Key Reminder Switch Input Circuit:

CIRCUIT OPERATION
The ETACS-ECU operates the following functions or systems according to signal from the key reminder switch:
- Ignition key reminder tone alarm function
- Keyless entry system
- Dome light dimming function
- Ignition key cylinder illumination light

TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the functions or systems described in "CIRCUIT OPERATION" do network normally.

TROUBLESHOOTING HINTS
- The key reminder switch may be defective.
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.
- The ETACS-ECU may be defective.

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe




STEP 1. Check key reminder switch connector C-207 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is key reminder switch connector C-207 in good condition?

YES: Go to Step 2.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. If the functions, which are described in "CIRCUIT OPERATION", work normally, the input signal from the key reminder switch should be normal.







STEP 2. Check the key reminder switch.
Disconnect key reminder switch connector C-207. Then check continuity between terminals.

Q: Is the key reminder switch in good condition?

YES: Go to Step 3.

NO: Replace the key reminder switch. If the functions described in "CIRCUIT OPERATION" work normally, the input signal from the key reminder switch should be normal.

STEP 3. Check the ground circuit to the key reminder switch. Measure the resistance at key reminder switch connector C-207.




1. Disconnect key reminder switch connector C-207 and measure the resistance available at the wiring harness side of the connector.




2. Measure the resistance value between terminal 4 and ground.
- The resistance should equal 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES: Go to Step 5.

NO: Go to Step 4.







STEP 4. Check the wiring harness between key reminder switch connector C-207 (terminal 4) and ground.

NOTE: Also check joint connector C-101 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-101 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection.

Q: Is the wiring harness between key reminder switch connector C-207 (terminal 4) and ground in good condition?

YES: No action is necessary and testing is complete.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. If the functions, which are described in "CIRCUIT OPERATION", work normally, the input signal from the key reminder switch should be normal.




STEP 5. Check ETACS-ECU connector C-227 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is ETACS-ECU connector C-227 in good condition?

YES: Go to Step 6.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. If the functions described in "CIRCUIT OPERATION" work normally, the input signal from the key reminder switch should be normal.







STEP 6. Check the wiring harness between key reminder switch connector C-207 (terminal 6) and ETACS-ECU connector C-227 (terminal 30).

Q: Is the wiring harness between key reminder switch connector C-207 (terminal 6) and ETACS-ECU connector C-227 (terminal 30) in good condition?

YES: Go to Step 7.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. If the functions, which are described in "CIRCUIT OPERATION", work normally, the input signal from the key reminder switch should be normal.

STEP 7. Check for continuity between key reminder switch connector C-207 terminal 4 and each of the other terminals as well as terminal 6 and each of the other terminals.




1. Disconnect key reminder switch connector C-207 and measure the resistance available at the equipment side of the connector.
2. Check for continuity between key reminder switch connector C-207 terminal 4 and each of the other terminals as well as terminal 6 and each of the other terminals.

Q: Does continuity exist between the terminals?

YES: Replace the ETACS-ECU. If the functions described in "CIRCUIT OPERATION" work normally the input signal from the key reminder switch should be normal.

NO: Replace the key reminder switch. If the functions described in "CIRCUIT OPERATION" work normally, the input signal from the key reminder switch should be normal.