Inspection Procedure 8
INSPECTION PROCEDURE 8: Auto-cruise Control Indicator Light inside Combination Meter does not Illuminate. (However, Auto-cruise Control is Normal.)Auto-cruise Control Indicator Light Drive Circuit Part 1:
Auto-cruise Control Indicator Light Drive Circuit Part 2:
CIRCUIT OPERATION
The power for the auto-cruise indicator in the combination meter is supplied from the ignition switch (IG1). When the auto-cruise control system is operating, the transistor inside the auto-cruise control-ECU illuminates the auto-cruise indicator through ECU terminal number 15.
TECHNICAL DESCRIPTION (COMMENT)
The cause is probably the malfunction of the indicator bulb or the malfunction of the connector or harness.
TROUBLESHOOTING HINTS
- Malfunction of the indicator bulb.
- Damaged harness or connector.
- Malfunction of the auto-cruise control-ECU.
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
STEP 1. Check the auto-cruise control indicator bulb.
1. Remove the combination meter .
2. Check the auto-cruise control indicator bulb.
Q: Is the bulb blown?
YES: Replace the bulb. Then check that the malfunction is eliminated.
NO: Go to Step 2.
STEP 2. Measure the signal voltage at auto-cruise control-ECU connector C-107 by backprobing.
1. Remove the auto-cruise control-ECU mounting nut.
2. Do not disconnect auto-cruise control-ECU connector C-107.
3. Turn the ignition switch to the "ON" position.
4. Measure the voltage between auto-cruise control-ECU connector C-107 terminal 15 and ground by backprobing.
- The measured voltage should measure battery positive voltage.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage battery positive voltage?
YES: Check that the malfunction is eliminated. If the malfunction is eliminated, replace the auto-cruise control-ECU. Then check that the malfunction is eliminated.
NO: Go to Step 3.
STEP 3. Measure the signal voltage at junction block connector C-214 by backprobing.
1. Do not disconnect junction block connector C-214. (2) Turn the ignition switch to the "ON" position.
3. Measure the voltage between junction block connector C-214 terminal 25 and ground by backprobing.
- The measured voltage should measure battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage battery positive voltage?
YES: Go to Step 5.
NO: Go to Step 4.
STEP 4. Check junction block connector C-211 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connector and terminals in good condition?
YES: Replace the junction block. Then check that the malfunction is eliminated.
NO: Repair or replace connector. Then check that the malfunction is eliminated.
STEP 5. Check combination meter connectors C-01, C-02 and intermediate connector C-21 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?
YES: Go to Step 6.
NO: Repair or replace connector. Then check that the malfunction is eliminated.
STEP 6. Check the harness wire between combination meter connector C-01 terminal 19 and junction block connector C-214 terminal 25 for damage.
Q: Is the harness wire in good condition?
YES: Go to Step 7.
NO: Repair the harness wire and then check that the malfunction is eliminated.
STEP 7. Check the combination meter.
1. Remove the combination meter and measure at the combination meter side .
2. Measure the continuity between combination meter C-01 terminal 9 and combination meter C-02 terminal 33.
- The measured continuity should be less than 2 Ohms.
3. Install the combination meter.
Q: Is the measured continuity less than 2 Ohms?
YES: Go to Step 8.
NO: Replace the combination meter . Then check that the malfunction is eliminated.
STEP 8. Check auto-cruise control-ECU connector C-107 and intermediate connector C-108 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?
YES: Go to Step 9.
NO: Repair or replace connector. Then check that the malfunction is eliminated.
STEP 9. Check the harness wire between combination meter connector C-02 terminal 33 and auto-cruise control-ECU connector C-107 terminal 15 for damage.
Q: Is the harness wire in good condition?
YES: Check that the malfunction is eliminated. If the malfunction is eliminated, replace the auto-cruise control-ECU. Then check that the malfunction is eliminated.
NO: Repair the harness wire and then check that the malfunction is eliminated.