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Home >> Saab >> 2001 >> 9-3 Base, 4D Hatchback, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 9 (TRIONIC T7 Fuel Control System) >> Adjustment-Replacement >> Leak test, fuel pressure, flow capacity and adaptation procedure >> Diagnostic procedure

Diagnostic procedure

WARNING: This page is about a different car, the 2003 Saab 9-3 and 2002 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
WARNING: Work involving removal of the fuel pressure regulator involves interference with the car fuel system. The following points should therefore be observed in connection with the procedure:
  • Ensure good ventilation! If there is approved ventilation for extraction of fuel fumes then this must be used.
  • Wear protective gloves! Prolonged exposure of the hands to fuel can cause irritation of the skin.
  • Have a fire extinguisher class BE at hand! Be aware of the risk for sparks, i.e. in connection with circuit breaking, short-circuiting, etc.
  • Absolutely No Smoking!
  • Wear protective glasses.
  1. Make 2 copies of the checklist at the end of this document. Fill out one of the copies before initiating diagnostic procedures.
  2. Connect TECH 2 .
  3. Remove the upper engine cover.
    Fig 1: Illustration For Steps 3-6
    G03576560Courtesy of SAAB-SCANIA OF AMERICA, INC.
  4. Using a T-pipe, connect 83 93 514 Charge pressure gauge  to the connection nipple for intake pressure on the engine's intake manifold.
  5. Disconnect the charge air pipe and wipe out the throttle body. Use a lint-free cloth moistened with 30 04 223 Electrical cleaner  .
  6. Coat the charge air pipe's O-ring with vaseline and mount it on the throttle body. If needed, replace the O-ring.

    Pressure test the system as follows: 

  7. Detach the crankcase ventilation hoses from the camshaft cover and from the pipe to the banjo fitting.
    Fig 2: Illustration For Steps 7-9
    G03576561Courtesy of SAAB-SCANIA OF AMERICA, INC.
  8. Plug the crankcase ventilation pipe at the cylinder head. Use the hose plug in the plug kit 83 95 659.
  9. Detach the hose from the check valve.
  10. Detach the hose from the mass air flow sensors. Fit plug kit 83 95 659 in the hose and connect the accompanying pressure regulator to an external air pressure outlet.
    Fig 3: Illustration For Steps 10-11
    G03576562Courtesy of SAAB-SCANIA OF AMERICA, INC.
    IMPORTANT: Close the pressure regulator before connecting it to the air pressure outlet.
  11. Detach and plug the upper signal hose to the boost pressure control valve (connection R).
  12. Detach the lower quick-release coupling from the EVAP canister purge valve.
    Fig 4: Illustration For Step 12
    G03576563Courtesy of SAAB-SCANIA OF AMERICA, INC.
  13. Pressurize the intake system by carefully turning the pressure regulator until a maximum 0.6 bar of overpressure is attained. The value should be monitored using the charge pressure gauge 83 93 514.
  14. The entire intake system is now pressurized and leaks can be located using leak detection spray or soapy water. Check all components, hoses and connections, and rectify any leaks that can be heard.
    IMPORTANT: Only leaks that can be heard will affect the function of the engine management system. When leak-detecting spray or soapy water is used, even small leaks will be found. These do not need to be addressed.
  15. Remove the plugs and connect the hoses to the mass air flow sensor, the boost pressure control valve, the EVAP canister purge valve and the crankcase ventilation.
  16. Check the control module's software version in TECH 2 . If there is a more recent version in WIS it should be programmed in to the control module.

    Checking fuel pressure/flow capacity 

    IMPORTANT: Use the assistance of a colleague when measuring on the move.
  17. Connect pressure measuring equipment 83 93 852 using adapter 83 94 744 to the connection nipple on the fuel rail. Lead the signal hoses and gauges for fuel pressure and intake pressure through the side window into the cabin. Make sure the hoses are not kinked or pinched.
    Fig 5: Illustration For Step 17
    G03576564Courtesy of SAAB-SCANIA OF AMERICA, INC.
  18. Measure fuel pressure while driving with as high a load as possible. Read the measurements on the manometers. The pressure differential should always be 3 bar of fuel pressure according to the table below.

    Drive thereafter with varying loads and engine speeds. Check that the fuel pressure follows the pressure in the intake manifold.

    If the pressure differential is incorrect, check the fuel pressure regulator, fuel pump and fuel lines (delivery and return). Check that the EVAP purge valve works. See EVAPORATIVE EMISSION SYSTEMS and EVAPORATIVE EMISSION SYSTEMS ORVR . Check for leaks in the evaporative emission system.

    FUEL PRESSURE SPECIFICATION

    Pressure, intake manifold Fuel pressure
    -0.6 to -0.4 bar 2.4-2.6 bar
    0 bar (atmospheric pressure) 3.0 bar
    0.6 bar 3.6 bar
  19. Check the fuel adaptation with the help of TECH 2 . Carry out the adaptation as follows:
    1. 19.a. Turn off the A/C or ACC.
    2. 19.b. Engine temperature should be over 80°C and the engine should have been running for at least 3.5 minutes. The adaptation must be completed within 10 minutes of engine start-up.
    3. 19.c. Drive on a flat road at between 1500 - 2750 RPM in 5th or 4th gear, attempting to keep the accelerator completely still for approximately 2 minutes.
    4. 19.d. Stop the car and let the engine idle.
    5. 19.e. Read "multiplicative adaptation" on TECH 2 .
    6. 19.f. Read "additive adaptation" on TECH 2 . If the value does not appear within 10 minutes, turn off and restart the engine and repeat steps 19b - 19f. If the value still does not appear, go to step  24.
  20. Carry out the adaptation of the throttle opening.
    1. 20.a. Coolant temperature should be over 80°C. Turn off the A/C or ACC.
    2. 20.b. Let the engine idle for 2 minutes. Turn off the engine.
    3. 20.c. Repeat step 20b 3 times.
  21. Fill out the second copy of the checklist.
  22. Disconnect the pressure measurement equipment and TECH 2 .
  23. Fit the upper engine cover.
  24. If the problems have not been solved, contact the importer's technical support. Have the checklists that were filled out ready.