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Home >> Alfa Romeo >> 2019 >> Giulia Base, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Collision/Avoidance >> (Active Cruise Control Module (Acc) - Electrical Diagnostics) >> DTC Troubleshooting >> C141C-86-Video Camera Private Can Communication Failure - Signal Invalid >> Diagnostic Test

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. With the scan tool, read Adaptive Cruise Control (ACC) DTCs and record on the repair order.
    2. With the scan tool, erase ACC Module DTCs.
    3. Turn the ignition off for ten seconds, then start the engine.
    4. With the scan tool, read ACC DTCs.

      Did the DTC return?

      Yes 

      • Go To  2

      No 

  2. CHECK THE PRIVATE CAN CIRCUITS FOR AN OPEN CIRCUIT OF HIGH RESISTANCE 
    1. Turn the ignition off.
    2. Disconnect the ACC Module harness connector.
    3. Disconnect the FFC Module harness connector.
    4. Measure the resistance of the (D469) Private CAN (+) circuit.
    5. Measure the resistance of the (D468) Private CAN (-) circuit.

      Is the resistance above 1.0 Ohm for either circuit?

      Yes 

      No 

      • Go To  3
  3. CHECK THE PRIVATE CAN CIRCUITS FOR A SHORT TO GROUND 
    1. Measure the resistance between ground and the (D469) Private CAN (+) circuit.
    2. Measure the resistance between ground and the (D468) Private CAN (-) circuit.

      Is the resistance below 1.0 Ohm for either circuit?

      Yes 

      No 

      • Go To  4
  4. CHECK THE PRIVATE CAN CIRCUITS FOR A SHORT TO VOLTAGE 
    1. Turn the ignition on.
    2. Measure the voltage of the (D469) Private CAN (+) circuit.
    3. Measure the voltage of the (D468) Private CAN (-) circuit.

      Is there voltage present on either circuit?

      Yes 

      No 

      • Go To  5
  5. CHECK FOR A SHORT BETWEEN THE (D469) PRIVATE CAN (+) CIRCUIT AND THE (D468) PRIVATE CAN (-) CIRCUIT 
    1. Turn the ignition off.
    2. Check for continuity between the (D469) Private CAN (+) Circuit and the (D468) Private CAN (-) Circuit.

      Is there continuity between the circuits?

      Yes 

      No 

      • Go To  6
  6. CHECK THE MODULE POWER SUPPLY CIRCUITS 
    1. Turn the ignition on.
    2. With a 12-volt test light connected to ground, check the (F741) Fused Ignition Run/Start Circuit at the ACC Module harness connector.
    3. With a 12-volt test light connected to ground, check the (F741) Fused Ignition Run/Start Circuit at the FFC Module harness connector.
      NOTE:

      The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

      Does the test light illuminate brightly for both power supply circuits?

      Yes 

      • Go To  7

      No 

  7. CHECK THE MODULE GROUND CIRCUITS 
    1. Turn the ignition off.
    2. With a 12-volt test light connected to 12 volts, check the (Z101) Ground Circuit at the ACC Module harness connector.
    3. With a 12-volt test light connected to 12 volts, check the (Z342) Ground Circuit at the FFC Module harness connector.
      NOTE:

      The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

      Does the test light illuminate brightly for both ground circuits?

      Yes 

      • Go To  8

      No 

  8. CHECK FORWARD FACING CAMERA (FFC) MODULE 
    1. Turn the ignition off.
    2. Replace the FFC Module in accordance with the Service Information.
    3. Turn the ignition on.
    4. With the scan tool, erase DTCs.
    5. Using the recorded information along with the When Monitored and Set Conditions above, operate the vehicle within the conditions that set the DTC.
    6. With the scan tool, read ACC DTCs.

      Did the DTC return?

      Yes 

      No