Circuit/System Verification

Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0033, P0034, P0035, P0236, P0237, P0238, P0244, P0245, or P0246 is not set.
If any of the DTCs are set, refer to Engine Management And Fuel System, V6 DTC Index for further diagnosis.
Verify the exhaust system is not restricted. Refer to RESTRICTED EXHAUST .
If DTC P0299 is set, verify the proper operation of the turbocharger bypass solenoid valve. Refer to TURBOCHARGER CLEANING AND INSPECTION
Engine running, command the Turbocharger Bypass Solenoid Valve between Inactive and Active with a scan tool while observing the following control circuit status parameters:
- Turbocharger Bypass Solenoid Valve Control Circuit High Voltage Test Status
- Turbocharger Bypass Solenoid Valve Control Circuit Open Test Status
- Turbocharger Bypass Solenoid Valve Control Circuit Low Voltage Test Status
  The parameters should alternate between OK and Not Run with each change in command.
Engine running, command the Turbocharger Wastegate Solenoid Valve to 20% with a scan tool while observing the following control circuit status parameters:
- Turbocharger Wastegate Solenoid Valve Control Circuit High Voltage Test Status
- Turbocharger Wastegate Solenoid Valve Control Circuit Open Test Status
- Turbocharger Wastegate Solenoid Valve Control Circuit Low Voltage Test Status
  Each parameter should display OK.
Determine the current vehicle testing altitude. Observe the scan tool Boost Pressure Sensor, and BARO Sensor parameters. Compare the parameters to each other and to the ALTITUDE VERSUS BAROMETRIC PRESSURE table. The parameters should be within the range specified in the table and within 2 kPa of each other.
Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.