Inspection Procedure O-7: 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.: Diagnosis
Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles communication interface
- MB991827: MUT-III USB cable
- MB991911: MUT-III Main harness B
- MB991813: SWS monitor kit
- MB991806: SWS monitor cartridge
- MB991812: SWS monitor harness (for column-ECU)
- MB991922: Probe harness
- STEP 1. Use scan tool MB991958 to select "ECU COMM Check" on the SWS monitor display.
Check the column-ECU.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958. Connect special tool MB991911 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.- Connect the special tool. Refer to "HOW TO CONNECT SWS MONITOR ."
- Turn the ignition switch to the "LOCK" (OFF) position.
- Operate scan tool MB991958 according to the procedure below to display "ECU COMM Check."
- Select "Interactive Diagnosis."
- Select "System Select."
- Select "SWS."
- Select "SWS MONITOR."
- Select "ECU COMM Check."
- Scan tool MB991958 should show "OK" on the "ECU COMM Check" menus for both the "COLUMN ECU" menus.
Q: Is "OK" displayed on the "COLUMN ECU" menu?
- YES: Go to Step 2.
- NO : Refer to INSPECTION PROCEDURE A-2: COMMUNICATION WITH THE COLUMN SWITCH (COLUMN-ECU) IS IMPOSSIBLE .
- STEP 2. Check the turn-signal light and lighting switch.
Remove the turn-signal light and the lighting switch. Then check continuity between the switch terminals.
TURN-SIGNAL LIGHT AND LIGHTING SWITCH POSITION AND SPECIFIED CONDITIONSWITCH POSITION TESTER CONNECTION SPECIFIED CONDITION OFF 1-2, 2-3, 2-11, 2-12, 5-9, 7-9 Open circuit Taillight switch 5-9 Less than 2 ohm Headlight switch 5-9, 7-9 Less than 2 ohm Passing switch 2-12 Less than 2 ohm Dimmer switch 2-11, 2-12 Less than 2 ohm Turn-signal light switch (LH) 1-2 Less than 2 ohm Turn-signal light switch (RH) 2-3 Less than 2 ohm Q: Is the turn-signal light and lighting switch in good condition?
- YES: Go to Step 3.
- NO : Replace it. The input signal from the column switch (turn-signal light and lighting switch) should be able to be checked and the functions, which are described in the TECHNICAL DESCRIPTION (COMMENT) should work normally.
- STEP 3. Replacement of ECU
- Replace the column switch.
- The input signal from the column switch (turn-signal light and lighting switch) should be able to be checked and the functions, which are described in the TECHNICAL DESCRIPTION (COMMENT) should work normally.
Q: Is the input signal from the column switch (turn-signal light and lighting switch) input normally?
- YES: There is no action to be taken.
- NO : Replace the ETACS-ECU. The input signal from the column switch (turn-signal light and lighting switch) should be able to be checked and the functions, which are described in the TECHNICAL DESCRIPTION (COMMENT) should work normally.