Inspection Procedure N-2

The ETACS-ECU does not receive any signal from the ignition switch (IG1).

Ignition Switch (IG1) Input Circuit:

CIRCUIT OPERATION
- The ETACS-ECU operates the following equipment or functions according to signal from the ignition switch (IG1):
- Ignition key reminder tone alarm function
- Light reminder tone alarm function
- Seat belt tone alarm function
- Power window timer function
- Sunroof timer function
- Seat belt warning light
- Headlight automatic shutdown function
- Turn-signal light
- Dome light dimming function
- Interior light automatic shutdown function
- Ignition key cylinder illumination light
- If the power supply circuit from the battery to the ETACS-ECU is open, this circuit is used as backup circuit.

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

TROUBLESHOOTING HINTS
- 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 ETACS-ECU connector C-226 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is ETACS-ECU connector C-226 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 ignition switch (IG1) should be normal.

STEP 2. Check the ignition switch (IG1) circuit to the ETACS-ECU. Measure the voltage at ETACS-ECU connector C-226.




1. Disconnect ETACS-ECU connector C-226 and measure the voltage available at the junction block side of the connector.
2. Turn the ignition switch to the "ON" position.




3. Measure the voltage between terminal 8 and ground.
- The voltage should equal approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES: Replace the ETACS-ECU. If the functions, which are described in "CIRCUIT OPERATION", work normally, the input signal from the ignition switch (IG1) should be normal.

NO: Go to Step 3.







STEP 3. Check the wiring harness between ETACS-ECU connector C-226 (terminal 8) and the ignition switch (IG1).

NOTE: Also check junction block connector C-211 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If junction block connector C-211 is damaged, Repair or replace the damaged components) as described in Harness Connector Inspection.

Q: Is the wiring harness between ETACS-ECU connector C-226 (terminal 8) and ignition switch (IG1) in good condition?

YES: No action is necessary and testing is complete.

NO: Replace the ETACS-ECU. If the functions, which are described in "CIRCUIT OPERATION", work normally, the input signal from the ignition switch (IG1) should be normal.