INSPECTION PROCEDURE J-5: Headlight, Taillight: Headlight automatic shutdown function does not work normally.: Diagnosis
Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991529: Diagnostic Trouble Code Check Harness
- STEP 1. Check the DTC.
Q: Does the DTC set when the ignition switch is turned to the "LOCK" (OFF) position?
YES : Carry out the troubleshooting by referring to Diagnostic Trouble Code Chart. Refer to DIAGNOSTIC TROUBLE CODE CHART .
NO: Go to Step 2 < when using scan tool MB991502 > or 3 < when using a voltmeter >.
- STEP 2. Check the input signal (by using scan tool MB991502).
Check the input signals from the following switches.
- Ignition switch (IG1)
- Driver's door switch
- Taillight switch
- Headlight 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.- Connect scan tool MB991502 to the data link connector.
- 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 : Go to Step 4.
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 ."
- The voltmeter needle does not fluctuate when the driver's door is opened: Refer to INSPECTION PROCEDURE O-8 "THE DRIVER'S OR PASSENGER'S DOOR SWITCH SIGNAL IS NOT SENT TO THE ETACS-ECU ."
- The voltmeter needle does not fluctuate when the lighting switch is turned from "OFF" to "TAIL": Refer to INSPECTION PROCEDURE O-14 "THE TAILLIGHT SWITCH SIGNAL IS NOT SENT TO THE ETACS-ECU ."
- The voltmeter needle does not fluctuate when the lighting switch is turned from "TAIL" to "HEAD": Refer to INSPECTION PROCEDURE O-14 "THE HEADLIGHT SWITCH SIGNAL IS NOT SENT TO THE ETACS-ECU ."
- STEP 3. Check the input signal (by using a voltmeter).
Check the input signals from the following switches.
- Ignition switch (IG1)
- Driver's door switch
- Taillight switch
- Headlight switch
- Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
- Check that the voltmeter indicator deflects once when the input signal enters.
Q: Does the voltmeter indicator deflect?
YES : Go to Step 4.
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 ."
- Scan tool MB991502 does not sound when the driver's door is opened: Refer to INSPECTION PROCEDURE O-8 "THE DRIVER'S OR PASSENGER'S DOOR SWITCH SIGNAL IS NOT SENT TO THE ETACS-ECU ."
- Scan tool MB991502 does not sound when the lighting switch is turned from "OFF" to "TAIL": Refer to INSPECTION PROCEDURE O-14 "THE TAILLIGHT SWITCH SIGNAL IS NOT SENT TO THE ETACS-ECU ."
- Scan tool MB991502 does not sound when the lighting switch is turned from "TAIL" to "HEAD": Refer to INSPECTION PROCEDURE O-14 "THE HEADLIGHT SWITCH SIGNAL IS NOT SENT TO THE ETACS-ECU ."
- STEP 4. Replacement of ECU.
- Replace the front-ECU.
- The headlight automatic shutdown function should work normally.
Q: Is the headlight automatic shutdown function working normally?
YES : No action is necessary and testing is complete.
NO: Replace the ETACS-ECU. The headlight automatic shutdown function should work normally.