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Home >> Alfa Romeo >> 2019 >> Giulia Base, AWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> (Heating & Air Conditioning - Electrical Diagnostics) >> DTC Troubleshooting >> B1903-15 - Distribution Defrost Right Motor Feedback-Circuit Short To Battery Or Open >> Diagnostic Test

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. With the scan tool, read HVAC DTCs and record on the repair order.
    2. Record the Environmental Data.
    3. With the scan tool, erase DTCs.
    4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    5. With the scan tool, read HVAC DTCs.

      Did the DTC return?

      Yes 

      • Go To  3

      No 

      • Go To  2
  2. PERFORM HVAC ACTUATOR CALIBRATION TEST 
    1. With the scan tool, perform the HVAC Actuator Calibration Test.

      Did this DTC change from Stored to Active while performing the HVAC Actuator Calibration Test?

      Yes 

      • Go To  6

      No 

      • Go To  3
  3. CHECK THE HARNESS CONNECTORS FOR DAMAGE 
    1. Check for loose, damaged or corroded connections on the Right Defrost Mode Door Actuator harness connector and HVAC Module harness connector.

      Are there any loose or damaged harness connectors?

      Yes 

      • Repair the wiring harness connectors as necessary.

      No 

      • Go to Step  4.
  4. CHECK (C328) RIGHT DEFROST MODE DOOR SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Turn the Ignition off.
    2. Disconnect the Right Defrost Mode Door actuator harness connector.
    3. Disconnect the HVAC Module harness connector.
    4. Using a multimeter, measure the resistance of the (C328) Right Defrost Mode Door Signal circuit between pin 2 of the Right Defrost Mode Door Actuator harness connector and pin 20 of the HVAC Module harness connector.

      Is the measurement above 3.0 Ohms?

      Yes 

      • Repair the (C328) Right Defrost Mode Door Signal circuit for an open circuit or high resistance.

      No 

      • Go to Step  5.
  5. CHECK (C328) RIGHT DEFROST MODE DOOR SIGNAL CIRCUIT FOR A SHORT TO BATTERY VOLTAGE 
    1. Turn the Ignition on.
    2. Using a multimeter, check for voltage in the (C328) Right Defrost Mode Door Signal circuit between pin 2 of the Right Defrost Mode Door Actuator harness connector and pin 20 of the HVAC Module harness connector.

      Is there any voltage present?

      Yes 

      • Repair the (C328) Right Defrost Mode Door Signal circuit for a short to the battery.

      No 

      • Go To  6
  6. CHECK THE RIGHT DEFROST MODE DOOR ACTUATOR FOR PROPER OPERATION 
    1. Replace the Right Defrost Mode Door Actuator in accordance with the Service Information. Refer to ACTUATOR, MODE DOOR, REMOVAL AND INSTALLATION .
    2. With the scan tool, erase HVAC DTCs and perform the HVAC Actuator Calibration Test.

      Did this DTC reset?

      Yes 

      • Go To  7

      No 

  7. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all HVAC Module harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Perform a terminal drag test on each connector terminal to verify proper terminal tension.

      Repair any conditions that are found.

    5. Reconnect all HVAC Module harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. With the scan tool, erase DTCs.
    9. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    10. With the scan tool, read HVAC Module DTCs.

      Did the DTC return?

      Yes 

      No 

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