LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Alfa Romeo >> 2019 >> Giulia Base, AWD >> Repair and Diagnosis >> Body & Frame >> Seats >> (Comfort Rear Seats Module (CRSM) - Electrical Diagnostics) >> DTC Troubleshooting >> U0101-8F-Lin Communication-Erratic >> Diagnostic Test

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. With the scan tool, read Comfort Rear Seat Module (CRSM) DTCs and record on the repair order.
    2. With the scan tool, erase CRSM DTCs.
    3. Turn the ignition off for ten seconds.
    4. Turn the ignition on.
    5. Operate all Heated Rear Seat Switch Assembly functions.
    6. With the scan tool, read CRSM DTCs.

      Did the DTC return?

      Yes 

      • Go To  2

      No 

  2. CHECK THE (D410) LIN BUS CIRCUIT FOR AN OPEN OR HIGH RESISTANCE 
    1. Turn the ignition off.
    2. Disconnect the CRSM connector(s).
    3. Disconnect the Rear Heated Seat Switch Assembly harness connector(s).
    4. Measure the resistance of the (D410) LIN Bus circuit between the Rear Heated Seat Switch Assembly connector and the CRSM connector.

      Is the resistance above 2.0 Ohms?

      Yes 

      • Repair the (D410) LIN Bus circuit for an open or high resistance.
      • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

      No 

      • Go To  3
  3. CHECK THE (D410) LIN BUS CIRCUIT FOR A SHORT TO GROUND 
    1. Check the continuity between ground and the (D410) LIN Bus circuit.

      Is there continuity between ground and the (D410) LIN Bus circuit?

      Yes 

      • Repair the (D410) LIN Bus circuit for a short to ground.
      • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK THE (D410) LIN BUS CIRCUIT FOR A SHORT TO VOLTAGE 
    1. Turn the ignition on.
    2. Measure the voltage of the (D410) LIN Bus circuit.

      Is there any voltage present?

      Yes 

      • Repair the (D410) LIN Bus circuit for a short to voltage.
      • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

      No 

      • Go To  5
  5. CHECK DTCS AFTER REPLACING THE HEATED REAR SEAT SWITCH ASSEMBLY 
    1. Turn the ignition off.
    2. Replace the Heated Rear Seat Switch Assembly in accordance with the Service Information. Refer to SWITCH, HEATED SEAT, REMOVAL AND INSTALLATION .
    3. Turn the ignition on.
    4. With the scan tool, erase CRSM DTCs.
    5. Turn the ignition off for ten seconds.
    6. Turn the ignition on.
    7. Operate all Heated Rear Seat Switch Assembly functions.
    8. With the scan tool, read CRSM DTCs.

      Did the DTC return?

      Yes 

      • Go To  6

      No 

  6. CHECK RELATED HARNESS CONNECTIONS 
    1. Turn the ignition off.
    2. Check the related component and module power supply and ground circuits.
    3. Disconnect all CRSM harness connectors.
    4. Disconnect all related in-line harness connections (if equipped).
    5. Disconnect the related component harness connectors.
    6. 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.
      • Check for spread terminals and verify proper terminal tension.

      Repair any conditions that are found.

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

      Did the DTC return?

      Yes 

      No