Inspection Procedure O-1
INPUT SIGNAL PROCEDURESINSPECTION PROCEDURE O-1: ETACS-ECU Does Not Receive Any Signal From The Ignition Switch (ACC).
Ignition Switch (ACC) Input Circuit (Part 1):
Ignition Switch (ACC) Input Circuit (Part 2):
CIRCUIT OPERATION
The ETACS-ECU operates the following equipment and function(s) according to signal from the ignition switch (ACC):
- Windshield wiper and washer
- Rear wiper and washer
- Interior light automatic-shutdown 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. Diagnostic Trouble Code Descriptions
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 Tool:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
STEP 1. Check ETACS-ECU connector C-219 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-219 in good condition?
YES: Go to Step 2.
NO: Repair or replace the damaged component(s). 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-219.
1. Disconnect ETACS-ECU connector C-219 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. 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-219 (terminal 4) and the ignition switch (ACC).
- Check the power supply line for open circuit and short circuit.
NOTE: Also check intermediate connector C-31 and junction block connector C-214 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-31 or junction block connector C-214 are damaged.
Q: Is the wiring harness between ETACS-ECU connector C-219 (terminal 4) and ignition switch (ACC) in good condition?
YES: Refer to Inspection Procedure 4: Defective power supply system of the ignition switch.
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.