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 DTCs P0090, P0091, P0092, P00C8, P00C9 and P00CA is not set.
- If any of the DTCs are set
  Refer to Circuit/System Testing below.
- Go to next step : If none of the DTCs are set
Engine at idle.
Verify the parameters listed below do not display Malfunction when commanding an increase and decrease in Fuel Rail Pressure with a scan tool :
- Fuel Pressure Regulator Control Circuit Low Voltage Test Status
- Fuel Pressure Regulator Control Circuit Open Test Status
- Fuel Pressure Regulator Control Circuit High Voltage Test Status
- Fuel Pressure Regulator High Control Circuit Low Voltage Test Status
- Fuel Pressure Regulator High Control Circuit Open Test Status
- Fuel Pressure Regulator High Control Circuit High Voltage Test Status
- If Malfunction is displayed
  Refer to Circuit/System Testing below.
- Go to next step : If Malfunction is not displayed
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.