Inspection Procedure 3

Inspection Procedure 3: ETACS-ECU does not receive any signal from the key reminder switch.


















COMMENTS ON TROUBLE SYMPTOM

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
- KOS
- Ignition key cylinder illumination light
- Interior 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 key reminder switch connector C-307 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is key reminder switch connector C-307 in good condition?

YES Go to Step 2.
NO Repair or replace the damaged component(s). Harness Connector Inspection. Check that the input signal of key reminder switch is normal.
STEP 2. Check the key reminder switch.

Disconnect key reminder switch connector C-307. 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. Check that the input signal of key reminder switch is normal.
STEP 3. Check the ground circuit to the key reminder switch. Measure the resistance at key reminder switch connector C-307.

(1)Disconnect key reminder switch connector C-307 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 be 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-307 (terminal 4) and grounding connector C-01 (terminal 11).

Check the ground wires for open circuit.

NOTE:
Also check joint connector C-108 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-108 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.

Q. Is the wiring harness between key reminder switch connector C-307 (terminal 4) and grounding connector C-01 (terminal 11) 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. Check that the input signal of key reminder switch is normal.
STEP 5. Check ETACS-ECU connector C-415 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is ETACS-ECU connector C-415 in good condition?

YES Go to Step 6.
NO Repair or replace the damaged component(s). Harness Connector Inspection. Check that the input signal of key reminder switch is normal.
STEP 6. Check the wiring harness between key reminder switch connector C-307 (terminal 6) and ETACS-ECU connector C-415 (terminal 13).

Check the output lines for open circuit and short circuit.

Q. Is the wiring harness between key reminder switch connector C-307 (terminal 6) and ETACS-ECU connector C-415 (terminal 13) in good condition?

YES Replace the ETACS-ECU. Check that the input signal of key reminder switch is normal.
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. Check that the input signal of key reminder switch is normal.