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Home >> Buick >> 2018 >> Enclave Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 38 (Engine Cooling System) >> Diagnostic Information and Procedures >> DTC P1258: Engine Coolant Overtemperature - Protection Mode Active >> Circuit/System Verification
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Circuit/System Verification

WARNING: This page is about a different car, the 2017 GMC Acadia Limited, 2017 Chevrolet Traverse, and 2017 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition ON.
  2. Verify DTC P0480, P0481, P0691, P0692, P0693, or P0694 is not set.
    • If no DTCs is set 
  3. NOTE:

    A short delay occurs before the ECM changes the cooling fan speed.

  4. Verify the cooling fan operates at each available speed as commanded with a scan tool.
    • Cooling fan operates 
  5. Verify that the engine does not overheat.
    • Engine does not overheat 
  6. Operate the vehicle within the Conditions for Running the DTC.
    • If the DTC does not set 
  7. All OK