Turbocharger: Testing and Inspection

Turbocharger and charge pressure regulating valve, checking

Special tools, testers and auxiliary items required





^ V.A.G 1397 A





^ VAS 5051 with VAS 5051/1

or

^ Scan tool V.A.G 1551 with V.A.G 1551/3 A

Requirements
^ All hoses and pipes must be securely fitted and free of leaks
^ DTC memory has been checked
^ Output diagnostic test mode has been performed
^ Vehicle diagnostic, testing and information system VAS 5051 or scan tool V.A.G 1551 must be connected

Test sequence

WARNING: To avoid any risk of accident, observe the safety precautions when using test instruments while road testing the vehicle.





^ Connect T - piece and measuring hose of turbocharger tester V.A.G 1397 A to intake manifold (front).
^ Route measuring hose under rear edge of hood and into passenger compartment via right- hand window.





^ Switch on turbocharger tester and set measuring range selector switch to position - I - (absolute pressure).
^ Connect measuring hose to connection - I -.

Notes:
^ Hose connections must be completely airtight, otherwise measurements will not be correct.
^ Ensure that measuring hose is not pinched at hood or side window.
^ Pressing memory key M on turbocharger tester will store the last measured value until memory key M is pressed again or the tester is switched off.
^ The decimal point in the display flashes to indicate that the value is being stored.
^ If the battery voltage of the turbocharger tester drops below the minimum level, an arrow will appear at the top left the display.
^ Before performing the test, drive the vehicle at a brisk speed for at least 3 km (without stopping at traffic lights etc.).
^ A second technician is required to note the readings on the tester when the vehicle is moving.





Indicated on display
^ Enter "08" to select the function "Read Measured Value Block" and confirm entry with Q key.





Indicated on display
^ Enter "004" to select display group 004 and confirm entry with Q key.





Indicated on display

Do not proceed with the test until the intake air temperature shown in display zone 4 is between 20 and 50°C. If necessary, run the engine until the required temperature is reached.
^ Press C key.





Indicated on display
^ Enter "115" to select display group 115 and confirm entry with Q key.





Indicated on display (1-4 = display zones)
^ Accelerate the vehicle from 2000 rpm at full throttle in third gear, and watch the rev counter.
^ When the engine speed reaches 3000 rpm, press the "PRINT" key on VAS 5051 (or V.A.G 1551) and at the same time press the memory key "M" on V.A.G 1397 A.

Notes: The charge pressure should be measured using turbocharger tester V.A.G 1397/A. Vehicle diagnostic, testing and information system VAS 5051 (or scan tool V.A.G 1551) is used to check whether the charge pressure is being registered by the control unit.





^ Specification for V.A.G 1397 A: 1.700 - 1.900 bar
^ Specification for VAS 5051 or V.A.G 1551: display zone 4 1700 - 1900 bar





If the specification is not attained or is exceeded:
^ Check DTC memory of engine control unit.





Malfunctions in charge pressure control function
1) If the charge pressure is too high the fuel supply will be interrupted in order to protect the engine, resulting in the misfiring at high engine speeds.