Test AK: Variable Geometry Turbocharger (VGT) Output
PINPOINT TEST AK: VARIABLE GEOMETRY TURBOCHARGER (VGT) OUTPUTFlow Chart:
This pinpoint test is intended to diagnose the following:
- Harness circuits: VGT, and VGTCH
- VGT actuator
- Powertrain control module (PCM) (12A650)
Variable Geometry Turbocharger (VGT) Actuator Connector
Variable Geometry Turbocharger (VGT) Actuator Connector:
PCM Connector
PCM Connector:
-----------------------------------------------
AK1 : PRELIMINARY DIAGNOSIS FOR DTC P0046
NOTE: Refer to the PCM and component connector pin numbers at the beginning of this pinpoint test
- Carry out a visual inspection.
- Retrieve and record all DTCs.
- Record the freeze frame data
- Clear the DTCs.
- Carry out the KOEO and KOER self-test. Quick Test Description
- Is DTC P0046 present?
-----------------------------------------------
AK2 : DIAGNOSTIC TROUBLE CODE (DTC) P0046
- Ignition OFF.
- VGT Actuator connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
- Is the voltage greater than 10.5 V?
-----------------------------------------------
AK3 : CHECK THE VGT ACTUATOR
- Ignition OFF.
- Connect a non-powered test lamp between:
- Ignition ON, engine OFF.
- Access the PCM and control the VGTDC PID.
- Command the VGT to less then 10% duty cycle
- Command the VGT to 85% duty cycle
- Does the test lamp go out as the VGT duty cycle is commanded low and illuminate as the duty cycle is commanded high?
-----------------------------------------------
AK4 : CHECK THE VGT CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect the test lamp
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
- Is the voltage less than 0.2 V?
-----------------------------------------------
AK5 : CHECK THE VGT CONTROL FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- Is the resistance greater than 10 kOhm?
-----------------------------------------------
AK6 : CHECK THE VGT CONTROL CIRCUIT FOR AN OPEN
- Measure the resistance between:
- Is the resistance less than 5 Ohm?
-----------------------------------------------
AK7 : CLEAN THE VGT ACTUATOR VALVE AND RETEST
NOTICE:
- The VGT actuator valve is sensitive to contamination. All work areas must be clean before starting this procedure. Do not allow contamination to enter the valve ports, cam follower, or turbocharger housing. Handle the VGT actuator by the solenoid body only. Do not attempt to wipe oil off the valve. Do not let the valve come in contact with materials that could contaminate the valve mechanism.
- Use only the Carburetor Tune-Up Cleaner PM-2 to spray the actuator valve. Brake cleaner or other solvents may damage the actuator valve.
- Remove the VGT actuator from the turbocharger assembly.
NOTE: Do not spray the zinc coated larger diameter housing, or electrical connector. Spray the valve with Carburetor Tune-Up Cleaner PM-2 while pressing the cam follower (tip of the actuator)
- Install the VGT actuator
- VGT Actuator connector connected.
- Ignition ON, engine running.
- Access the PCM and control the VGTDC PID.
- Access the PCM and control the RPM PID.
- Increase the commanded engine speed to 1,250 RPM using output state control. The calibration may limit the actual RPM between 1,150 and 1,200 RPM
- Increase the VGT duty cycle to greater then 70%
- Decrease the VGT duty cycle to 0%
- Does the turbocharger pitch change when the VGT duty cycle is increased and decreased?
-----------------------------------------------
AK8 : CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
