Circuit/System Verification

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Chevrolet Suburban, and 2018 Cadillac Escalade ESV. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON.
Verify DTC U18A2 is not set or stored in history.
- If DTC U18A2 is set or stored in history
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If DTC U18A2 is not set or stored in history
Verify that DTC P018B, P018C, P018D, P0231, P0232, P023F, P0641, P0606, P1255, P129E or P12A6 is not set.
- If any of the DTCs are set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If none of the DTCs are set
Verify the scan tool Fuel Pressure Sensor and the Desired Fuel Pressure are within 45 kPa (6.5 PSI) at 300 kPa (43.5 PSI) request or 60 kPa (8.7 PSI) at 400 kPa (58 PSI) request of each other while operating the vehicle through varying loads.
WARNING: Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.
- If greater than 45 kPa (6.5 PSI)/60 kPa (8.7 PSI)
  Refer to Circuit/System Testing below.
- Go to next step: If less than 45 kPa (6.5 PSI)/60 kPa (8.7 PSI)
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set.
- If the DTC sets
  Refer to Circuit/System Testing below.
- Go to next step: If the DTC does not set
All OK.