Inspection Procedure 8
Check the Circuit (Power Supply Line) from the Battery to the ETACS-ECU.ETAC-ECU's Battery Circuit:
CIRCUIT OPERATION
Refer to ETACS-ECU Power Supply and Scan Tool Communication Circuit. The ETACS-ECU is always energize by the battery.
TECHNICAL DESCRIPTION (COMMENT)
If that power supply circuit is defective, the circuit flowing through the ignition switch (IG1) will function as a backup circuit. In this case, the following is at "LOCK" (OFF) position.
- Light reminder tone alarm function
- Ignition key reminder tone alarm function
- Central door locking system
- Dome light dimming function
- Theft alarm system
TROUBLESHOOTING HINTS
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
- MB991223: Test Harness Set
STEP 1. Check the battery circuit at the ETACS-ECU connector D-11.
1. Disconnect the ETACS-ECU connector D-11 and measure the harness side.
2. Measure the Voltage between terminal 2 and ground.
Q: Is the voltage approximately 12 volts (battery positive voltage)?
YES: Replace the ETACS-ECU. The functions, which are described in the "Technical Description (comment)," should work normally.
NO: Go to Step 2.
STEP 2. Check ETACS-ECU connector D-11 for damage.
Q: Is ETACS-ECU connector D-11 in good condition?
YES: Go to Step 3.
NO: Repair or replace it. Refer to Harness Connector Inspection. The functions, which are described in the "Technical Description (comment)," should work normally.
STEP 3. Check the harness wires between ETACS-ECU connector D-11 and battery.
NOTE: After checking junction block connector D-01 and OD or storage connector A-54X, check the wires. If junction block connector D-01 and OD or storage connector A-54X are damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Are the harness wires between ETACS-ECU connector D-11 and battery in good condition?
YES: There is no action to be taken.
NO: Repair them The functions, which are described in the "Technical Description (comment)," should work normally.