Turbocharger and Wastegate, Checking
Turbocharger and wastegate, checking
If special testing equipment is required during test drive, heed the following WARNING:
WARNING!
^ When driving or riding in an airbag equipped vehicle, NEVER hold the scan tool or other test equipment in your hands or lap while in motion. Objects between you and the airbag increase the risk of injury in an accident.
^ During a test drive in an airbag-equipped vehicle, test equipment must always be fastened to and operated from the rear seat by a second technician.
Special tools and equipment
^ VAG1397A turbocharger tester
^ VAG1551 scan tool with VAG1551/3 adapter
Test conditions:
^ Perform output diagnostic test mode (function 03)
^ Minimum engine oil temperature: 60°C (140°F)
^ All vacuum connections are free of leaks
Test procedure
^ Using T-fitting, connect VAG1397A turbocharger tester test hose to front of intake manifold.
^ Guide test hose over rear corner of hood through right window opening into vehicle interior.
^ Turn turbocharger tester on and select measuring range -1- (absolute pressure).
^ Connect test hose to connection flange -1-.
Note:
^ Hoses must be connected so there is no possibility of leaks, otherwise incorrect readings may result.
^ Ensure test hose is not pinched at the hood and/or window.
^ By pressing the memory button "M" on the turbocharger tester, the last test value is stored until either memory button "M" is pressed again or the turbocharger tester is shut off.
^ A blinking comma in the display field indicates a value has been stored.
^ An arrow appears in the top left comer of the display field if the turbocharger tester battery voltage drops below the allowed specification.
^ Before testing, drive vehicle briskly for at least 3 km (approximately 2 miles) without frequent stops.
WARNING!
^ Always use a second technician to take measurements via the VAG1397A turbocharger tester when test-driving vehicle for this test.
Vehicles with manual transmission:
^ Accelerate vehicle in 3rd gear at full throttle from 2000 RPM and watch tachometer.
^ At 3000 RPM press memory button "M" on turbocharger tester.
Specification: 1.37 - 1.47 bar (19.865 - 21.315 psi)
Vehicles with automatic transmission:
^ Drive with selector lever in range 2.
^ Accelerate to 3000 RPM and wait for transmission to shift into 2nd gear.
^ Press accelerator pedal to kickdown position (transmission will not shift down at this vehicle/engine speed).
^ At 4500 RPM, press memory button "M" on turbocharger tester.
Specification: 1.3 - 1.4 bar (18.85 - 20.30 psi)
Note: For vehicles with automatic transmission the boost pressure test may not always provide a definitive reading of proper boost pressure regulation. If pressure readings are at the lower end of the specified range, measure boost pressure control via load signal.
All vehicles:
Note: If no boost exists and a rumbling sound is heard from the engine compartment, the causes are as follows:
^ Charge pressure bypass valve malfunctioning.
^ Vacuum line to charge pressure bypass valve leaking or disconnected.
^ Boost pressure control (via load signal), checking
WARNING!
^ Always use a second technician to take measurements via the VAG1397A turbocharger tester when test-driving vehicle for this test.
Note: If VAG1551 scan tool is not available, use VAG1552 mobile scan tool instead.
^ Unclip Data Link Connector (DLC) cover.
^ Using VAG1551/3 adapter, connect VAG1551 Scan Tool (ST) or VAG1552 mobile scan tool.
Indicated on display 1)
1) Operating modes 1 and 2 are displayed alternately
Note: If nothing appears on display.
Refer to Scan tool operating instructions
^ Press button 1 to select "Rapid data transfer" operating mode 1.
^ Start engine.
Indicated on display
^ Press buttons -0- and -1-to insert "Engine Electronics" address word 01.
^ Press -Q- button to confirm input.
VAG1551 scan tool display indicates control module coding.
^ Press -> button.
Indicated on display
^ Press buttons -0- and -8- to select "Read Measuring Value Block" function 08.
^ Press -Q- button to confirm input.
Indicated on display
^ Press buttons -1-, -1- and -4- to input display group number 114 (114).
^ Press -Q- button to confirm input.
The "Read Measuring Value Block" displays four display fields. Interpreting values 1-4 in each display field.
Interpreting display fields
Indicated on display:
^ Note values in display field 2 and 3 while vehicle is under steady acceleration.
Specification
Deviation between display field 2 and 3: 0.3 ms (maximum)
Note: If the OBD for the Engine Control Module (ECM) recognizes Diagnostic Trouble Codes (DTCs) in boost pressure regulation, duty cycle (display field 4) will indicate a constant 5%.
Diagnostic Trouble Codes (DTC) for boost pressure regulation