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Home >> Alfa Romeo >> 2019 >> Giulia Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> 2.0L - DTCS P2237-00 To P2AE1-00 >> DTC Troubleshooting >> P26AB-00-Engine Coolant Bypass Valve "A" Stuck >> Diagnostic Test

Diagnostic Test

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

      Did the DTC return?

      Yes 

      • Go To  2

      No 

  2. CHECK THE COOLANT LEVEL AND COOLING SYSTEM OPERATION 
    NOTE:

    Diagnose and repair any Coolant Bypass Valve control circuit faults before continuing with this test procedure.

    NOTE:

    Address any cooling system issues before continuing with this test procedure.

    1. Visually inspect the Low Temperature Cooling System hoses for any signs of a pinched or kinked hoses restricting flow through the heater.
    2. Ensure that the coolant is at the proper level and properly bled (no air in system).
    3. Check the cooling system for proper flow through the Coolant Bypass Valve, Intercooler and Low Temperature Radiator.

      Were any issues found?

      Yes 

      • Perform the appropriate repair. Clear the DTC and retest the vehicle in accordance with the monitoring conditions.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  3
  3. REPLACE THE COOLANT BYPASS VALVE AND RETEST FOR DTCS 
    1. Replace the Coolant Bypass Valve in accordance with the Service Information.
    2. Turn the ignition on.
    3. Using the recorded Freeze Frame Data and the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    4. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go To  4

      No 

  4. CHECK RELATED PCM AND COMPONENT CONNECTIONS 
    1. Perform any Service Bulletins that apply.
    2. Disconnect all PCM harness connectors.
    3. Disconnect all related in-line harness connections (if equipped).
    4. Disconnect the related component harness connectors.
    5. 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.

    6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    9. With the scan tool, erase DTCs.
    10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    11. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      No 

      • The wiring or poor connection problem has been repaired.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .