INSPECTION PROCEDURE 9: Auto-cruise Control Indicator Light Inside Combination Meter does not Illuminate. (However, Auto-cruise Control is Normal.): Diagnosis

Required Special Tool: 

• MB991223: Harness Set

1. STEP 1. Check the auto-cruise control indicator bulb. 
   1. Remove the combination meter. (Refer to COMBINATION METER ASSEMBLY AND VEHICLE SPEED SENSOR ).
   2. Check the auto-cruise control indicator bulb.

   Q: Is the bulb blown? 

   YES  : Replace the bulb. Go to  Step 6.

   NO:  Go to Step 2.

2. STEP 2. Measure the signal voltage at auto-cruise control-ECU connector C-52 by backprobing. 
   1. Do not disconnect auto-cruise control switch connector C-21.
   2. Turn the ignition switch to the "ON" position.
      Fig 1: Disconnecting Auto-Cruise Control Switch Connector C-21

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   3. Measure the voltage between auto-cruise control-ECU connector C-52 terminal 15 and ground by backprobing.
      • The 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  : Check that the malfunction is eliminated. If the malfunction is eliminated, it can be assumed that this malfunction is intermittent. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ). If the malfunction is not eliminated, replace the auto-cruise control-ECU (Refer to AUTO-CRUISE CONTROL  ), and then Go to  Step 6.

   NO:  Go to Step 3.

   Fig 2: Measuring Voltage Between Auto-Cruise Control-ECU Connector C-52 Terminal 15 And Ground

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3. STEP 3. Check auto-cruise control-ECU connector C-21, combination meter connector C-101 and junction block connector C-308 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are the connector and terminals in good condition? 

   YES  : Go to Step 4.

   NO:  Repair or replace the faulty connector. (Refer to , HARNESS CONNECTOR INSPECTION ). Go to  Step 6.

   Fig 3: Checking Auto-Cruise Control-ECU Connector C-21

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   Fig 4: Checking Combination Meter Connector C-101

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   Fig 5: Checking Junction Block Connector C-308

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4. STEP 4. Check the combination meter. 
   1. Remove the combination meter and measure at the combination meter side. (Refer to COMBINATION METER ASSEMBLY AND VEHICLE SPEED SENSOR ).
   2. Measure the continuity between combination meter C-101 terminal 12 and terminal 9.
      • 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 5.

   NO:  Repair or replace connector. (Refer to , HARNESS CONNECTOR INSPECTION ). Go to  Step 6.

   Fig 6: Measuring Continuity Between Combination Meter C-101 Terminal

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5. STEP 5. Check the harness wire between auto-cruise control-ECU connector C-21 terminal 15 and junction block connector C-308 terminal 25 for damage. 

   Q: Are the harness wires in good condition? 

   YES  : It can be assumed that this malfunction is intermittent. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ). Go to Step 6.

   NO:  Repair the damaged harness wire. Go to Step 6.

   Fig 7: Checking Harness Wire Between Auto-Cruise Control-ECU Connector C-21

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   Fig 8: Checking Junction Block Connector C-308

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6. STEP 6. Check that the malfunction is eliminated. 

   Q: Is the malfunction eliminated? 

   YES  : This procedure is complete.

   NO:  Go to  Step 1.