GF07.51-P-2002D | Starting HFM-SFI function | 19.7.96 |
ENGINE 104.941 up to 31.7.96
except CODE (491) as of Model Year 97 USA version
except CODE (498) as of Model Year 97 Japanese version
ENGINE 104.942 /945 /992
ENGINE 104.943 /944 /991 /994 up to 31.7.96
ENGINE 104.995 except CODE (491) as of Model Year 97 USA version
ENGINE 111.921 /942 up to 31.8.98
ENGINE 111.945 up to 31.8.98 in MODEL 202.020 /080
ENGINE 111.945 up to 31.5.98 in MODEL 208.335
ENGINE 111.946 up to 31.5.98
ENGINE 111.960 /961 /970 /977
ENGINE 111.944 /975 up to 31.7.96
ENGINE 111.974
except CODE (491) as of Model Year 97 USA version
except CODE (498) as of Model Year 97 Japanese version
15.03.07 | The document has been updated to this date and will no longer be subject to revision. |
Start control
Additional fuel has to be injected during the starting operation, irrespective of the coolant temperature, in order to facilitate starting of the engine when cold. The increased quantity of fuel injected is achieved by extending the injection time.
Battery voltage and voltage supply
The quantity of fuel injected is determined by the opening times of the fuel injection valves. This opening time is dependent on the battery voltage. In order to achieve the same quantity of fuel injected if e.g. the battery voltage is lower, the HFM-SFI control module extends the injection time. It is not possible to start the engine if battery voltage is less than about 7 V.
Post-start enrichment
Enrichment with additional fuel is necessary for a short time after starting the engine when cold. This enrichment compensates for the fuel which precipitates onto the cylinder barrels, and the engine runs smoothly.
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Synchronizing fuel injection and firing order
The sequence is synchronized during the initial engine revolutions in order to achieve correct assignment of the fuel injection and firing order to the respective cylinder. The HFM-SFI control module requires the signals from the camshaft position or Hall-effect sensor and crankshaft position sensor for this purpose.
Ignition during engine start
When the engine is started and up to about 500 rpm, ignition timing is controlled only through the signals from the camshaft position or Hall-effect sensor. A transition from the fixed ignition timing point to the ignition timing point calculated for the momentary operating state only occurs once engine speed has reached about 600 rpm.
The infrared remote control module overrides the engine control module in order to achieve the drive authorization system. The system blocks the engine management. Although the starter rotates, the engine does not start.
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Battery | |||
Ignition/starter switch | Circuitry of circuit 50 see Wiring Diagrams Group 15 | ||
Starter | |||
| Fuel supply (HFM-SFI) function | ||
| Ignition system (HFM-SFI) function | ||
| Start quantity control function | ||
| Synchronization of fuel injection and firing order function | with increment control | |
| Synchronization of fuel injection and firing order with segment control function | ||
| Information on selector lever position function | with automatic transmission | |
| Starter control function | Model 170 with engine 111 and manual transmission | |
Model 170 with engine 111 and automatic transmission |
Referenced documents
- gf0713p3000d DFI start quantity control function
- gf0751p3001d HFM-SFI ignition system function
- gf0751p3004d Fuel supply system HFM-SFI function
- gf0751p4009d HFM-SFI synchronizing fuel injection and firing order function
- gf0761p4009d ME-SFI synchronizing fuel injection and firing order function
- gf0761p4029f Selector lever position information function
- gf1530p3000g Starter control, function
- gf1530p3000ga Starter control, function