Circuit/System Verification

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

Ignition On/Vehicle in Service Mode.
Verify DTC U0074 or U18A2 is not set or stored in history.
- If DTC U0074 or U18A2 is set or stored in history
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If DTC U0074 or U18A2 is not set or stored in history
Verify that DTC P018B, P018C, P018D, P0231, P0232, or P023F 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 Short Term Fuel Pump Trim and the Long Term Fuel Pump Trim when multiplied together are less than 1.5.
- If greater than 1.5
  Refer to Circuit/System Testing.
- Go to next step: If less than 1.5
Command the Fuel Pressure to 300 kPa (43.5 psi) using the scan tool Control Function: Fuel Pressure Increase/Decrease.
Verify the scan tool parameter: Fuel Pressure Sensor & Desired Fuel Pressure are within 45 kPa (6.5 psi) of each other at 300 kPa (43.5 psi) request.
- If greater than 45 kPa (6.5 psi)
  Refer to Circuit/System Testing.
- Go to next step: If less than 45 kPa (6.5 psi)
Command the Fuel Pressure to 400 kPa (58 psi) using the scan tool Control Function: Fuel Pressure Increase/Decrease.
Verify the scan tool parameter: Fuel Pressure Sensor & Desired Fuel Pressure are within 60 kPa (8.7 psi) of each other at 400 kPa (58 psi) request.
- If greater than 60 kPa (8.7 psi)
  Refer to Circuit/System Testing.
- Go to next step: If less than 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.
- Go to next step: If the DTC does not set
All OK.