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Home >> Alfa Romeo >> 2019 >> Giulia Base, AWD >> Repair and Diagnosis >> Accessories & Equipment >> Collision/Avoidance >> (Active Cruise Control Module (Acc) - Electrical Diagnostics) >> DTC Troubleshooting >> C1200-16-Battery Voltage - Circuit Voltage Below Threshold >> Diagnostic Test

Diagnostic Test

  1. CHECK THE PCM FOR RELATED DTCS 
    1. Start the engine.
    2. With the scan tool, read Powertrain Control Module (PCM) DTCs and record on the repair order.

      Are there any PCM charging or battery related DTCs set?

      Yes 

      • Repair the DTC(s) set in the PCM. Refer to DTC INDEX .

      No 

      • Go To  2
  2. CHECK FOR AN ACTIVE DTC 
    1. With the scan tool, read Adaptive Cruise Control (ACC) DTCs and record on the repair order.

      Is the DTC active?

      Yes 

      • Go To  3

      No 

  3. CHECK THE (F741) IGNITION RUN/START OUTPUT CIRCUIT FOR AN OPEN OR HIGH RESISTANCE 
    1. Turn the ignition off.
    2. Disconnect the ACC Module harness connector.
    3. Turn the ignition on.
    4. With a 12-volt test light connected to ground, check the (F741) Ignition Run/Start Output circuit at the ACC 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?

      Yes 

      • Go To  4

      No 

      • Repair the circuit for an open or high resistance.
        NOTE:

        If the fuse is open, make sure to check for a short to ground.

      • Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to ADAPTIVE CRUISE CONTROL VERIFICATION TEST .
  4. CHECK THE (Z101) GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE 
    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.
      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?

      Yes 

      • Go To  5

      No 

  5. CHECK RELATED WIRING AND HARNESS CONNECTIONS 
    1. Disconnect all related 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 ACC 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 information along with the When Monitored and Set Conditions above, operate the vehicle within the conditions that set the DTC.
    10. With the scan tool, read ACC DTCs.

      Did the DTC return?

      Yes 

      No