Inspection Procedure L-5

Column Switch: ETACS-ECU does not receive Any Signal from the Taillight Switch, the Headlight Switch, the Passing Light Switch, the Dimmer Switch, the Turn-signal Light Switch or Switch

Turn-signal Light And Lighting Switch Input Circuit:

CIRCUIT OPERATION
The ETACS-ECU operates the following equipment or functions according to signal from the column switch (turn-signal light and lighting switch):
- Light reminder tone alarm function
- Headlight
- Turn-signal light

TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the equipment or functions, which are described in "CIRCUIT OPERATION", do not work normally. If the signal is not normal, the column switch (turn-signal light and lighting switch) or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
- Malfunction of column switch (turn-signal light and lighting switch)
- Malfunction of the ETACS-ECU
- Damaged harness wipes or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991862: SWS monitor kit







STEP 1. Use scan tool to select "ECU CHECK" on the SWS monitor display.

Check the column-ECU.

CAUTION: To prevent damage to scan toot MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502. Also connect SWS monitor kit MB991862 after turning on scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector.
2. Connect SWS monitor kit MB991862 to the column switch connector.
3. When the ignition switch is turned to the "ON" position, scan tool MB991502 should show "OK" on the "COLUMN ECU" menu.

Q: Is "OK" displayed on the "COLUMN ECU" menu?

YES: Go to Step 2.

NO: Refer to Inspection Procedure A-2 "Communication with column switch (column-ECU) is impossible."

STEP 2. Replace the ECU.

1. Replace the column switch (turn-signal light and lighting switch).
2. If the functions, which are described in "CIRCUIT OPERATION", work normally, the input signal from the column switch (turn-signal light and lighting switch) should be normal.

Q: Does the column switch (turn-signal light and lighting switch) send normal signal to the ECU?

YES: No action to be taken.

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