INSPECTION PROCEDURE J-7: Headlight, taillight: High-beam indicator light does not illuminate.: Diagnosis

Required Special Tool: 

• MB991223: Test Harness Set

1. STEP 1. Verify the headlights (high-beam and passing) operation. 

   Q: Do the headlights (high-beam and passing) illuminate normally? 

   YES  : Go to Step 2.

   NO:  Solve the problem first. Refer to SYMPTOM CHART  .

2. STEP 2. Check the high-beam indicator light circuit at the ETACS-ECU connector C-318. 
   1. Disconnect the ETACS-ECU connector C-318 and measure at the wiring harness side.
      Fig 1: Identifying ETACS-ECU Connector C-318

      Courtesy of DAIMLERCHRYSLER CORPORATION
   2. Connect terminal 72 to the ground.

   Q: Does the high-beam indicator light illuminate? 

   YES  : Go to  Step 8.

   NO:  Go to Step 3.

   Fig 2: Connecting Terminal 72 To Ground

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3. STEP 3. Check the battery power supply circuit to the combination meter. Test at combination meter connector C-101. 
   1. Disconnect the combination meter connector C-101 and measure the voltage available at the wiring harness side of the connector.
      Fig 3: Identifying Combination Meter Connector C-101

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   2. Measure the voltage between terminal 4 and ground.
      • The voltage should equal approximately 12 volts (battery positive voltage).

   Q: Is the measured voltage approximately 12 volts (battery positive voltage)? 

   YES  : Go to  Step 6.

   NO:  Go to Step 4.

   Fig 4: Measuring Voltage Between Terminal 4 And Ground

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4. STEP 4. Check the combination meter connector C-101 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is combination meter connector C-101 in good condition? 

   YES  : Go to Step 5.

   NO:  Repair or replace the damaged component(s). Refer to , HARNESS CONNECTOR INSPECTION . The high-beam indicator light should work normally.

   Fig 5: Identifying Combination Meter Connector C-101

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5. STEP 5. Check the wiring harness between combination meter connector C-101 (terminal 4) and battery. 
   Fig 6: Identifying Combination Meter Connector C-101

   Courtesy of DAIMLERCHRYSLER CORPORATION
   NOTE: Also check junction block connector C-308 and C-313 and intermediate connector C-209 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If junction block connector C-308 or C-313 or intermediate connector C-209 is damaged, repair or replace the damaged component(s) Refer to , HARNESS CONNECTOR INSPECTION .

   Q: Are the wiring harness between combination meter connector C-101 (terminal 4) and battery in good condition? 

   YES  : No action is necessary and testing is complete.

   NO:  Repair or replace them. The high-beam indicator light should work normally.

   Fig 7: Identifying Intermediate Connector C-209

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   Fig 8: Identifying Junction Block Connector C-308 And C-313

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6. STEP 6. Check the combination meter connector C-101 and ETACS-ECU connector C-318 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are combination meter connector C-101 and ETACS-ECU connector C-318 in good condition? 

   YES  : Go to Step 7.

   NO:  Repair or replace the damaged component(s). Refer to , HARNESS CONNECTOR INSPECTION . The high-beam indicator light should work normally.

   Fig 9: Identifying Combination Meter Connector C-101

   Courtesy of DAIMLERCHRYSLER CORPORATION
   Fig 10: Identifying ETACS-ECU Connector C-318

   Courtesy of DAIMLERCHRYSLER CORPORATION
7. STEP 7. Check the wiring harness between combination meter connector C-101 (terminal 5) and ETACS-ECU connector C-318 (terminal 72). 

   Q: Is the wiring harness between combination meter connector C-101 (terminal 5) and ETACS-ECU connector C-318 (terminal 72) in good condition? 

   YES  : Replace the combination meter (printed circuit board). The high-beam indicator light should work normally.

   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 high-beam indicator light should work normally.

   Fig 11: Identifying Combination Meter Connector C-101

   Courtesy of DAIMLERCHRYSLER CORPORATION
   Fig 12: Identifying ETACS-ECU Connector C-318

   Courtesy of DAIMLERCHRYSLER CORPORATION
8. STEP 8. Replacement of ECU. 
   1. Replace the ETACS-ECU.
   2. The high-beam indicator light should work normally.

   Q: Is the high-beam indicator light working normally? 

   YES  : No action is necessary and testing is complete.

   NO:  Replace the front-ECU. The high-beam indicator light should work normally.