Inspection Procedure K-1
INSPECTION PROCEDURE K-1: Flasher timer: Turn-signal lights does not flash when the turn-signal light switch is turned on.
Connectors:
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)
Is 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
- 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 hazard warning light operation.
Q: Do the hazard warning lights work normally?
YES : Go to Step 7
NO : Go to Step 2.
STEP 2. Verify the turn-signal light state operation.
Q: Does any turn-signal lights flash?
YES (only one side illuminates): Go to Step 3.
NO (no lights flash at all): Go to Step 4.
STEP 3. Check the ETACS-ECU connector C-319 and junction block connectors C-301, C-308 and C-312 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are ETACS-ECU connector C-319 and junction block connectors C-301, C-308 and C-312 in good condition?
YES : Replace the ETACS-ECU. The turn-signal lights should flash normally.
NO : Repair or replace the damaged component(s). Refer to Harness Connector Inspection. The turn-signal lights should flash normally.
STEP 4. Check the power supply circuit to the ETACS-ECU. Test at ETACS-ECU connector C-319.
1. Disconnect the ETACS-ECU connector C-319 and measure at the junction block side.
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. The turn-signal lights should flash normally.
NO : Go to Step 5.
STEP 5. Check the ETACS-ECU connector C-319 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-319 in good condition?
YES : Go to Step 6.
NO : Repair or replace the damaged components). Refer to Harness Connector Inspection. The turn-signal lights should flash normally.
STEP 6. Check the wiring harness between ETACS-ECU connector C-319 (terminal 11) and battery.
NOTE: Also check junction block connector C-312 and intermediate connector C-209, check the wires. If junction block connector C-312 and intermediate connector C-209 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Are the wiring harness between ETACS-ECU connector C-319 (terminal 11) and 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. The turn-signal lights should flash normally.
STEP 7. Check the input signal (by using scan tool MB991502).
Check the input signals from the following switches.
- Ignition switch (IG1)
- Turn-signal light switch
CAUTION : To prevent damage to scan tool MB991502, always turn the ignition switch to the 'LOCK' (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Check that the tone alarm of scan tool MB991502 sounds when the input signal enters.
Q: Does the tone alarm of scan tool MB991502 sound when the input signal enters?
YES : Replace the ETACS-ECU. The turn-signal lights should flash normally.
NO :
- Scan tool MB991502 does not sound when the ignition switch is turned from "ACC" to "ON": Refer to Inspection Procedure O-2 "The ignition switch (IG1) signal is not sent to the ETACS-ECU." Inspection Procedure O-2
- Scan tool MB991502 does not sound when the turn-signal light switch is turned from "OFF" to "left turn" and "right turn": Refer to Inspection Procedure O-14 "The turn signal light switch signal is not sent to the ETACS-ECU ." Diagnostic Aids
STEP 8. Check the input signal (by using a voltmeter).
Check the input signals from the following switches.
- Ignition switch (IG1)
- Turn-signal light switch
1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. Check that the voltmeter indicator deflects once when the input signal enters.
Q: Does the voltmeter indicator deflect?
YES : Replace the ETACS-ECU. The turn-signal lights should flash normally.
NO :
- The voltmeter needle does not fluctuate when the ignition switch is turned from "ACC" to "ON": Refer to Inspection Procedure O-2 "The ignition switch (IG1) signal is not sent to the ETACS-ECU." Inspection Procedure O-2
- The voltmeter needle does not fluctuate when the turn-signal light switch is turned from "OFF" to "left turn" and "right turn": Refer to Inspection Procedure O-14 "The turn signal light switch signal is not sent to the ETACS-ECU." Inspection Procedure O-14