Inspection Procedure M-1

INSPECTION PROCEDURE M-1: ETACS-ECU does not receive any signal from the ignition switch (ACC).


















CIRCUIT OPERATION

The ETACS-ECU operates the following equipment and function(s) according to signal from the ignition switch (ACC):

- Windshield wiper and washer
- Interior light automatic shutoff function
The ETACS-ECU receives information on the ignition switch condition (ACC) from the middle-grade multi center display unit via CAN communication. If the ignition switch (ACC) input signal is incorrect, refer to the appropriate Diagnostic Trouble Code Chart Simplified Wiring System (SWS).

TECHNICAL DESCRIPTION (COMMENT)

If the signal is not normal, the equipment and function(s), which are described in "CIRCUIT OPERATION", do not work 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-217 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q. Is ETACS-ECU connector C-217 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" works normally, the input signal from the ignition switch (ACC) should be normal.

STEP 2. Check the ignition switch (ACC) line of the power supply circuit to the ETACS-ECU. Measure the voltage at ETACS-ECU connector C-217.





(1)Disconnect ETACS-ECU connector C-217 and measure the voltage available at the junction block side of the connector.
(2)Turn the ignition switch to the "ACC" position.





(3)Measure the voltage between terminal 4 and ground.

- The voltage should measure approximately 12 volts (battery positive voltage).

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

YES Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Immobilizer System. If the equipment described in "CIRCUIT OPERATION" works normally, the input signal from the ignition switch (ACC) should be normal.

NO Go to Step 3.

STEP 3. Check the wiring harness between ETACS-ECU connector C-217 (terminal 4) and the ignition switch (ACC).

- Check the power supply line for open circuit and short circuit.













NOTE:
Also check intermediate connector C-24 and junction block connector C-203 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-24 or junction block connector C-203 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection Harness Connector Inspection.

Q. Is the wiring harness between ETACS-ECU connector C-217 (terminal 4) and ignition switch (ACC) in good condition?

YES Malfunction of the Ignition Switch Power Supply System.

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" works normally, the input signal from the ignition switch (ACC) should be normal.