Inspection Procedure O-14

INSPECTION PROCEDURE O-14: Column switch: The taillight switch, headlight switch, passing light switch, dimmer switch or turn-signal light switch signal is not sent to the ETACS-ECU.






CIRCUIT OPERATION
The ETACS-ECU uses the input signal from the column switch (turn-signal light and lighting switch) to operate various functions.

TECHNICAL DESCRIPTION (COMMENT)
The column switch (turn-signal light and lighting switch) input signal is used to operate the following devices or functions:
- Light reminder tone alarm function
- Headlight
- Turn-signal light
- Fog light
If the signal fails, these devices will not work normally.

TROUBLESHOOTING HINTS
- The column switch (turn-signal light and lighting switch) may be defective
- The ETACS-ECU may be defective
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS
Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991529: Diagnostic Trouble Code Check Harness

STEP 1. Verify the ignition switch positions.

Q: Does a diagnostic trouble code set when the ignition switch is at any of the positions?

YES: Carry out the troubleshooting by referring to the Diagnostic Trouble Code Chart.

NO: Go to Step 2.




STEP 2. Check the turn-signal light and lighting switch.

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
1. Replace the column switch.
2. 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 : No action is necessary and testing is complete.

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.