Trionic T8 Fuel Control System: Overview Saab 9-3 II

Scheme 35

Scheme 36

1. Remove the upper engine cover.
2. Place a receptacle to collect spilled oil.
3. Unplug the connector.
4. Remove the oil pressure switch. Tool 83 95 187 (27 mm fitting).

Scheme 37

Scheme 38

1. Fit the oil pressure switch with new steel and wipe away any spilled oil. Tightening torque 18 Nm (13 lbf ft).
2. Plug in the connector.
3. Remove the receptacle.
4. Connect an exhaust extractor and start the engine to check its function.
5. Switch off the engine.
6. Replace the upper engine cover.

Scheme 39

1. Remove the connector from the control valve.
2. Press down the catch carefully with a screwdriver and remove the control valve from its mounting.
3. Detach the hoses from the valve.

Scheme 40

1. Fit the valve to its mounting.
2. Connect the hoses to the valve. Turbine housing Turbocharger diaphragm box Turbocharger inlet hose Make sure the hoses are not pinched together and adjust as necessary.
3. Plug in the connector.

Scheme 41

Scheme 42

1. Remove the upper engine cover.
2. Undo the cap on the expansion tank to release pressure, retighten the cap.
3. Unplug the connector to the coolant temperature sensor.
4. Have some paper ready to collect any spilled coolant.
5. Remove the coolant temperature sensor. Use «83 96 087 SOCKET, COOLANT TEMPERATURE SENSOR»(ref-275835-S42864659532007122900000) B207.

Scheme 43

Scheme 44

1. Quickly fit the coolant temperature sensor with new seal. Tightening torque 15 Nm (11 lbf ft).
2. Plug in the coolant temperature sensor connector.
3. Top up with coolant as necessary.
4. Replace the upper engine cover.

Scheme 45

1. Unplug the connector.
2. Remove the mass air flow sensor.

Scheme 46

1. Fit the mass air flow sensor with a new O-ring, sparingly lubricated with Vaseline.
2. Plug in the connector.

Overview

1. «ENGINE TORQUE CONTROL»(ref-275835-S21522933172007122900000)
2. «REQUEST FOR ENGINE TORQUE, 1X»(ref-275835-S00653979262007122900000)
3. «LIMITATION OF ENGINE TORQUE, 2X»(ref-275835-S21552946892007122900000)
4. «LIMITATION OF VEHICLE SPEED, 3X»(ref-275835-S12654506892007122900000)
5. «MINIMUM ENGINE TORQUE, 4X»(ref-275835-S30967709572007122900000)
6. «MAXIMUM ENGINE TORQUE, 5X»(ref-275835-S08867872632007122900000)
7. «EMISSION-DEPENDENT TORQUE LIMITATION, 6X»(ref-275835-S12159246722007122900000)
8. «SAFETY-RELATED TORQUE LIMITATION, 7X»(ref-275835-S28161215772007122900000)
9. «PEDAL REQUEST»(ref-275835-S38507442412007122900000)
10. «LOAD COMPENSATION»(ref-275835-S08995385782007122900000)
11. «THROTTLE CONTROL»(ref-275835-S19855476142007122900000)
12. «TURBO CONTROL»(ref-275835-S34182413512007122900000)
13. «FUEL INJECTION, BASIC FUNCTION»(ref-275835-S08969444762007122900000)
14. «BASIC FUEL QUANTITY»(ref-275835-S13460818872007122900000)
15. «COMPENSATION»(ref-275835-S03043262642007122900000)
16. «CLOSED LOOP»(ref-275835-S28957130762007122900000)
17. «VENTILATION»(ref-275835-S01707830802007122900000)
18. «FUEL ADAPTATION»(ref-275835-S03800436832007122900000)
19. «STARTING FUEL»(ref-275835-S33497243212007122900000)
20. «INJECTION DURATION»(ref-275835-S14562975382007122900000)
21. «FUEL SHUT-OFF»(ref-275835-S11555156162007122900000)
22. «INJECTORS»(ref-275835-S05918137422007122900000)
23. «IGNITION, BASIC FUNCTION»(ref-275835-S23047287562007122900000)
24. «IDLING SPEED IGNITION TIMING»(ref-275835-S13094260382007122900000)
25. «CATALYTIC CONVERTER HEATING IGNITION»(ref-275835-S05137461642007122900000)
26. «COMPENSATION»(ref-275835-S12215046972007122900000)
27. «NORMAL IGNITION TIMING»(ref-275835-S38332247152007122900000)
28. «KNOCK CONTROL»(ref-275835-S08601835922007122900000)
29. «STARTING IGNITION TIMING»(ref-275835-S21998693712007122900000)
30. «IGNITION SYSTEM»(ref-275835-S02840010062007122900000)
31. «IONIZATION CURRENT MEASUREMENT»(ref-275835-S22769250492007122900000)

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Scheme 51

1. Driver request, 10 The control module reads the voltage from pedal potentiometer 1 and converts it to a torque request.
2. Cruise control, 11 With cruise control active, the torque required to maintain the set speed is calculated.
3. Idle, 12
4. Select highest value 1x requests torque to keep the engine running. The highest value (select high) of functions 10 (pedal) and 11 (cruise control) is selected. Function 12 (idle) gives torque to keep the engine running when the pedal is released and cruise control (11) is inactive.
5. Engine torque limitation 2x are torque limitations of what is requested from the box above. Here, the lowest value (select low) of 1x and 2x is selected. Maximum torque varies depending on the engine variant. Furthermore, engine torque when driving must be limited to protect the engine, gearbox, brakes and turbocharger. Even external units such as TCM or TCS/ESP can limit engine torque. Engine torque is also limited by certain system faults.
6. Select low Control module selects lowest value.
7. Limitation of vehicle speed Engine torque can be limited to limit the maximum speed (31) of the car.
8. Select low Control module selects lowest value from function 2x and limitation of vehicle speed, 31.
9. Torque increase 4x If requested torque is lower than is necessary to maintain stable combustion, if the wheels slip during engine braking or if dashpot is required, the engine torque can be increased slightly. Request is sent to box 11.
10. Select highest value Control module selects highest value.
11. Torque reduction, engine protection Engine torque can be reduced to protect the engine from e.g. knocking.
12. Select low Control module selects lowest value.
13. Limitation of torque increase This function dampens rapid changes in torque request to reduce transient enrichment.
14. Safety limitation 7x is a Select Low together with maximum permitted air mass/combustion when pedal released. Only for safety and as a final check. This result is the total air mass that is to pass the engine per combustion.
15. Select low Control module selects lowest value.
16. Compensation Compensation for the torque required for e.g. A/C compressor and generator operation.
17. Total compensation The control module totals all the values.
18. Total requested torque This value is the system's total torque request.
19. Conversion Nm to mg/c Conversion torque (Nm) to air mass/combustion (mg/c).
20. Throttle control Requested air mass per combustion is converted to a voltage for throttle potentiometer 1. Charge air pressure and temperature are used to correct the conversion. The throttle motor turns the throttle until the value for throttle potentiometer 1 agrees with the requested value.
21. Current air mass/combustion Requested air mass/combustion is compared with the current air mass/combustion (MAF actual). In case of a deviation, the requested voltage for throttle position sensor 1 will be adjusted.
22. Turbo control If the requested air mass/combustion is too great to be handled by throttle control only, control will be transferred to the turbo control. The excess is converted to a PWM that controls the charge air control valve. The value is corrected by the value from the atmospheric pressure sensor.
23. Current air mass/combustion The requested air mass/combustion is compared with the current air mass/combustion and the charge air control valve PWM is adjusted if necessary.

Scheme 52

Engine torque control is used to ensure the correct engine torque is supplied by the engine. ECM controls engine torque by regulating the air mass per combustion and also by regulating the ignition timing.

Generally, it can be said that engine torque control has one slow method of regulating torque, air mass control, and one fast method, ignition timing control.

Scheme 53

The fast method of regulation is used when the engine load changes rapidly, e.g. idle when turning the steering wheel rapidly so that the power steering pump puts a load on the engine. The increased torque requirement from the engine must then be compensated by a rapid increase in engine torque or the idling speed will drop. This fast compensation is done using an advanced ignition, giving higher torque.

After the fast compensation, ECM will gradually increase the throttle area in order to get more air mass into the engine while the ignition is retarded slightly. This allows ECM to maintain a torque reserve so that it can again perform fast compensation for changed engine loads.

Scheme 54

The opposite takes place when the load is quickly reduced, e.g. when turning off the A/C compressor. The engine will then produce a higher torque than is required to keep the engine running and its auxiliary equipment, i.e. generator, power steering pump and water pump. Unless the engine torque is quickly reduced, idling speed will rise above the nominal due to the engine producing "too much torque".

Engine torque is reduced by retarding the ignition slightly, which results in lower engine torque and restores the balance between the torque being produced and the torque being used.

Now, the engine will not be running with an optimal ignition timing with regard to fuel consumption and ECM will reduce the throttle area (less air mass to the engine) while the ignition will be advanced slightly.

Scheme 55

Slow engine torque control is used when driving under constant load, i.e. when the load does not vary or varies slowly. In this case, ECM operates mainly with throttle area to regulate the engine torque.

For higher torque requirements, turbo control will also be used to increase the air mass in the engine so that it produces the requested engine torque.

Scheme 56