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INSPECTION PROCEDURE 2: Malfunction of the A/C control panel Power Supply System.
 
 
 
 
 
 
TECHNICAL DESCRIPTION (COMMENT)
The A/C control panel power system may be defective if the air conditioning, defogger, and outside/inside air selection damper motor all do not operate normally.
 
 
 
TROUBLESHOOTING HINTS
  • Malfunction of the A/C control panel
  • Damaged wiring harness or connectors
 
 
 
DIAGNOSIS
Required Special Tool:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Check A/C control panel connector C-210 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Is A/C control panel connector C-210 in good condition?
Go to Step 2.
Repair or replace the connector. Refer to GROUP 00E, Harness Connector Inspection . Check that the A/C works normally.
 
STEP 2. Measure the voltage at A/C control panel connector C-216.
(1) Disconnect A/C control panel connector C-216 and measure the voltage at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 20 and ground.
  • The measured value should be approximately 12 volts (battery positive voltage).
Is the measured voltage approximately 12 volts?
Go to Step 5.
Go to Step 3.
 
STEP 3. Check ETACS-ECU connector C-417 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Is ETACS-ECU connector C-417 in good condition?
Go to Step 4.
Repair or replace the connector. Refer to GROUP 00E, Harness Connector Inspection . Check that the A/C works normally.
 
STEP 4. Check the wiring harness between A/C control panel connector C-216 (terminal 20) and ETACS-ECU connector C-417 (terminal 5).
  • Check the A/C control panel power supply line for open circuit.
noteAlso check joint connector C-04 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-04 is damaged, repair or replace the connector as described in GROUP 00E, Harness Connector Inspection .
Is the wiring harness between A/C control panel connector C-216 (terminal 20) and ETACS-ECU connector C-417 (terminal 5) in good condition?
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
Repair the wiring harness. Check that the A/C works normally.
 
STEP 5. Measure the voltage at A/C control panel connector C-216.
(1) Disconnect A/C control panel connector C-216 and measure the voltage at the harness side.
(2) Measure the voltage between terminal 10 and ground.
  • The measured value should be approximately 12 volts (battery positive voltage).
Is the measured voltage approximately 12 volts?
Go to Step 7.
Go to Step 6.
 
STEP 6. Check the wiring harness between A/C control panel connector C-216 (terminal 10) and the fusible link (36).
noteAlso check ETACS-ECU connectors C-406 and C-417 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If ETACS-ECU connectors C-406 and C-417 is damaged, repair or replace the connector as described in GROUP 00E, Harness Connector Inspection .
  • Check the A/C control panel power supply line for open circuit.
Is the wiring harness between A/C control panel connector C-210 (terminal 13) and the fusible link (36) in good condition?
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
Repair the wiring harness. Check that the A/C works normally.
 
STEP 7. Measure the resistance at A/C control panel connector C-216.
(1) Disconnect A/C control panel connector C-216, and measure at the wiring harness side.
(2) Measure the resistance between terminal 9 and ground.
  • The measured value should be 2 ohms or less.
Does the measured resistance value correspond with this range?
Replace the A/C control panel, and check that the A/C works normally.
Go to Step 8.
 
STEP 8. Check grounding connector C-01 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Is grounding connector C-01 in good condition?
Go to Step 9.
Repair or replace the connector. Refer to GROUP 00E, Harness Connector Inspection .
 
STEP 9. Check the wiring harness between A/C control panel connector C-216 (terminal 9) and grounding connector C-01 (terminal 6).
  • Check the A/C control panel ground line for open circuit.
Is the wiring harness between A/C control panel connector C-216 (terminal 9) and grounding connector C-01 (terminal 6) in good condition?
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
Repair the wiring harness. Check that the A/C works normally.