Inspection Procedure 9

Inspection Procedure 9: After ASC Switch is Turned OFF, TCL/ASC System cannot be Disabled.

ASC OFF Switch Circuit:

SYSTEM OPERATION
The ETACS-ECU terminal No. 15 is earthed by pressing the ASC switch. The active or not active state of the ASC switch is transferred from ETACS-ECU to ASC-ECU via the CAN bus line.

TECHNICAL DESCRIPTION (COMMENT)
This may be caused by the open circuit in the ASC switch circuit.

PROBABLE CAUSES
^ Damaged wiring harness and connectors
^ ASC switch malfunction
^ Malfunction of ETACS-ECU

DIAGNOSIS

Required Special Tools:
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface (V.C.I.)
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A

STEP 1. Voltage measurement at C-313 ETACS-ECU connector
^ Measure the voltage between the terminal No. 15 and the body ground.
OK: Approximately 5 volts

Q: Is the check result normal?
YES: Go to Step 4.
NO: Go to Step 2.

STEP 2. Connector check: C-313 ETACS-ECU connector, C-26 intermediate connector, C-10 ASC switch connector
Q: Is the check result normal?
YES: Go to Step 3.
NO: Repair the defective connector.

STEP 3. ASC switch check
Q: Does the check result vary?
YES: Repair the wiring harness between the C-313 ETACSECU connector terminal No. 15 and the ground.
NO: Go to Step 4.

STEP 4. Retest the system.
Q: Does ASC turn ON and OFF normally using the ASC switch?
YES: An intermittent malfunction may be present.
NO: Replace the ETACS-ECU, and then go to Step 5.

STEP 5. Retest the system.
Q: Does ASC turn ON and OFF normally using the ASC switch?
YES: The procedure is complete.
NO: Return to Step 1.