Inspection Procedure K-1
Flasher Timer: Turn-signal lights do not flash when the turn-signal light switch is turned on.NOTE: This troubleshooting procedure requires the use of scan tool MB991958 and SWS monitor kit MB991813. For details on how to use the SWS monitor, refer to "How to use SWS monitor."
Turn-Signal Light Power Supply Circuit Part 1:
Turn-Signal Light Power Supply Circuit Part 2:
CIRCUIT OPERATION
- The turn-signal light switch sends a signal through the column-ECU (incorporated in the column switch) to the ETACS-ECU. If the column-ECU sends a turn-signal light switch "ON" signal to the ETACS-ECU, the ETACS-ECU turns on the flasher timer (incorporated in the ETACS-ECU), thus causing the turn-signal lights to flash.
- The ETACS-ECU operates the turn-signal lights according to the following signals:
- Ignition switch (IG1)
- Turn-signal light switch
TECHNICAL DESCRIPTION (COMMENT)
If the turn-signal lights do not flash normally, the input circuits from the switches described in "CIRCUIT OPERATION" or the ETACS-ECU may be defective. If the hazard warning lights do not flash, the power supply line to the ETACS-ECU (dedicated to the turn-signal lights) may be defective.
TROUBLESHOOTING HINTS
- Trouble in input signal system
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- The ETACS-ECU may be defective
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991911: M.U.T.-III Main Harness B
- MB991813: SWS monitor kit
- MB991806: SWS monitor cartridge
- MB991812: SWS monitor harness (for column-ECU)
- MB991922: Probe harness
STEP 1. Verify the hazard warning light.
Q: Does the hazard warning light work normally?
YES: Go to Step 7.
NO: Go to Step 2.
STEP 2. Verify the turn-signal lights.
Q: Do either of the turn-signal lights illuminate?
YES: (illuminates at only one side): Go to Step 3.
NO: (do not illuminate at all): Go to Step 4.
STEP 3. Check ETACS-ECU connector C-226, junction block connectors C-210, C-214 and C-217 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are ETACS-ECU connector C-226, junction block connectors C-210, C-214 and C-217 in good condition?
YES: Replace the ETACS-ECU. Verify that the turn-signal lights illuminate normally.
NO: Repair or replace the damaged components). Refer to Harness Connector Inspection. Verify that the turn-signal lights illuminate normally.
STEP 4. Check ETACS-ECU connector C-226 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-226 in good condition?
YES: Go to Step 5.
NO: Repair or replace the damaged components). Refer to Harness Connector Inspection. Verify that the turn-signal lights illuminate normally.
STEP 5. Check the battery power supply circuit to the ETACS-ECU. Measure the voltage at ETACS-ECU connector C-226.
1. Disconnect ETACS-ECU connector C-226 and measure the voltage available at the junction block side of the connector.
2. Measure the voltage between terminal 11 and ground.
- The voltage should equal approximately 12 volts (battery positive voltage).
Q: Is the measured voltage approximately 12 volts (battery positive voltage)?
YES: Replace the ETACS-ECU. Verify that the turn-signal lights illuminate normally.
NO: Go to Step 6.
STEP 6. Check the wiring harness between ETACS-ECU connector C-226 (terminal 11) and the battery.
NOTE: Also check intermediate connector C-129 and junction block connector C-210 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-129 or junction block connector C-210 is damaged, repair or replace the damaged components) as described in Harness Connector Inspection.
Q: Is the wiring harness between ETACS-ECU connector C-226 (terminal 11) and the battery in good condition?
YES: No action is necessary and testing is complete.
NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the turn-signal lights illuminate normally.
STEP 7. Check the input signal by using "FUNCTION DIAG." menu of the SWS monitor.
Check the input signals from the following switches:
- Ignition switch: ON
- Turn-signal light switch: RH
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.
1. Connect the special tool. Refer to "How to connect SWS monitor."
2. Operate scan tool MB991958 according to the procedure below to display "TURN SIG.RH."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "TURN SIGNAL."
g. Select "TURN SIG.RH."
3. Check that normal conditions are displayed for the items described in the table.
Q: Does the scan tool MB991958 display the items "T/S RH SW" and "IG SW (IG1)" as normal condition?
YES
NO
NO
STEP 8. Check the input signal by using "FUNCTION DIAG." menu of the SWS monitor.
Check the input signal from the turn-signal light switch (LH).
1. Operate scan tool MB991958 according to the procedure below to display "TURN SIG.LH."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "TURN SIGNAL."
g. Select "TURN SIG.LH."
2. Check that normal condition is displayed for the item described in the table.
Q: Does the scan tool MB991958 display the item "T/S LH SW" as normal condition?
YES: Replace the ETACS-ECU. Verify that the turn-signal lights illuminate normally.
NO: Refer to Inspection Procedure N-6 "The ETACS-ECU does not receive any signal from the turn-signal light switch."