The Instant Start function - GF15.20-P-3002IC
ENGINE 648.961 in MODEL 211.026 with CODE (494) USA version
The electronically controlled preheating system I nstant S tart s ystem (ISS) allows spontaneous starting with the key.
The voltage on the glow plugs is managed by the glow time output stage, depending on time and voltage, in such a way that an extremely short pre and starting glowing time and controlled after-glowing are achieved. The advantages of this during cold start and in the warm-up phase are as follows:
- A short preheating time
- Stabile idling
- Low exhaust gas emissions
- Good response behavior
- A controllable preheating temperature
The glow time output stage is connected over a serial data interface with the CDI control unit. The CDI control unit provides the glow time output stage with various parameters such as motor speed, engine load and coolant temperature over the serial data interface.
Actuation of the glow plugs is determined over the performance map (glow plug voltage and glowing time) stored in the glow time output stage depending on the operating condition of the engine.
Preglowing
Preglowing serves to rapidly achieve the glow plug temperature which is necessary to start the engine.
The glow time output stage and the preglow indicator lamp are also actuated by "ignition ON" over the CDI control unit.
The glow plugs have the battery voltage applied for a short time directly from the glow time output stage.
Start readiness preheating
Start readiness preheating assures a sufficiently high temperature after preglowing until the engine is started. Here the glow plugs are pulsed by the Glow time output stage.
Start-up glowing
Start-up glowing supports achievement of the idle speed during the starting procedure.
The preglow indicator lamp lights up and goes out after expiry of the start-up glowing time.
After-glowing
After-glowing serves to support combustion in a cold engine and is controlled according to a performance map.
Intermediate glowing
Intermediate glowing supports combustion when there are long stretches driven in the overrun. This lowers the exhaust gas emissions.
Diagnosis glowing
Diagnosis glowing serves self diagnosis of the individual glow power circuits and glow plugs.
The glow plugs are energized at a lower temperature level whereby a system error is recognized and stored in the fault memory.
Diagnosis glowing can also be actuated for diagnostic purposes using STAR DIAGNOSIS.
Emergency glowing
If a problem in communication via the serial data interface occurs (e.g. discontinuity, short circuit), then the emergency glowing function is actuated over "circuit 15". Substitute value for the glow time and the glow plug voltage are use by the glow time output stage.
Preglow indicator lamp
The preglow indicator lamp is actuated by the CDI control unit for:
- a component or line defect in the glow system
- Start-glowing
The glow time is a maximum of 3 seconds during "limp-home".
5 V glow plugs are used!
The glow time output stage still actuates the glow plugs for a minimum battery voltage of 8 V.
Vent line heater element
The vent line heater element prevents freezing of the crankcase ventilation system by condensate and plugging up of the crankcase ventilation system by non-volatile oil residues.
| Component description for the crankshaft position sensor | L5 | GF07.04-P-6010IC | |
| Component description for the coolant temperature sensor | B11/4 | GF07.04-P-6040IC | |
| Component description for the CDI control unit | N3/9 | GF07.16-P-6000IC | |
| Component description for the vent line heater element | R39/1 | GF09.00-P-4010IC | |
| Component description for the glow time output stage | N14/3 | GF15.20-P-4010IC | |
| Component description for glow plugs | R9 | GF15.20-P-4020IC | |
| Component description for the accelerator pedal sensor | B37 | GF30.20-P-2010IC |