Inspection Procedure N-2

INSPECTION PROCEDURE N-2: ETACS-ECU does not receive any signal from the hazard warning light switch.














CIRCUIT OPERATION

The ETACS-ECU operates the following functions or systems according to signal from the hazard warning light switch:

- Hazard warning light
- Keyless entry system (registering the encrypted code)

TECHNICAL DESCRIPTION (COMMENT)

If the signal is not normal, the equipment or systems described in "CIRCUIT OPERATION" do not work normally.

TROUBLESHOOTING HINTS

- The hazard warning light 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 hazard warning light switch connector C-08 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q. Is hazard warning light switch connector C-08 in good condition?

YES Go to Step 2.

NO Repair or replace the damaged component(s). Harness Connector Inspection. If the equipment described in "CIRCUIT OPERATION" work normally, the input signal from the hazard warning light switch should be normal.

STEP 2. Check the hazard warning light switch.





Remove the hazard warning light switch. Service and Repair. Then check continuity between the switch terminals.





Q. Is the hazard warning light switch in good condition?

YES Go to Step 3.

NO Replace the hazard warning light switch. If the equipment described in "CIRCUIT OPERATION", work normally the input signal from the hazard warning light switch should be normal.

STEP 3. Check the ground circuit to the hazard warning light switch. Measure the resistance at hazard warning light switch connector C-08.





(1)Disconnect hazard warning light switch connector C-08 and measure the resistance available at the wiring harness side of the connector.





(2)Measure the resistance value between terminal 2 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 hazard warning light switch connector C-08 (terminal 2) and ground.

- Check the ground wire for open circuit.





Q. Is the wiring harness between hazard warning light switch connector C-08 (terminal 2) 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 equipment described in "CIRCUIT OPERATION" work normally, the input signal from the hazard warning light switch should be normal.

STEP 5. Check ETACS-ECU connector C-218 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q. Is ETACS-ECU connector C-218 in good condition?

YES Go to Step 6.

NO Repair or replace the damaged component(s). Harness Connector Inspection. If the equipment described in "CIRCUIT OPERATION" work normally, the input signal from the hazard warning light switch should be normal.

STEP 6. Check the wiring harness between hazard warning light switch connector C-08 (terminal 1) and ETACS-ECU connector C-218 (terminal 55).

- Check the communication lines for open circuit and short circuit.









Q. Is the wiring harness between hazard warning light switch connector C-08 (terminal 1) and ETACS-ECU connector C-218 (terminal 55) in good condition?

YES Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Immobilizer System. If the equipment described in "CIRCUIT OPERATION" work normally, the input signal from the hazard warning light switch should be 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. If the equipment described in "CIRCUIT OPERATION" work normally, the input signal from the hazard warning light switch should be normal.