GF15.20-P-3004P CDI Glow Function

GF15.20-P-3004P CDI Glow Function
ENGINE 642 in MODEL 164.1 /8, 203.2, 251.1, 203.0, 251.0 up to Model Year 2008 /YoM 07
ENGINE 642 in MODEL 209.4, 211.0, 219.3, 211.2, 209.3, 211.6
ENGINE 642 in MODEL 461.3
ENGINE 642.9 in MODEL 463.3 up to 31.5.12

The preglow system warms up the engine combustion chamber to the temperature required for ignition of the fuel-air mixture. For preheating, one differentiates between the following conditions:
^ Preglowing
^ Start-ready glowing
^ Start-glowing
^ Afterglowing
^ Diagnostic glowing
^ Diesel particulate filter (DPF) preheating
^ Emergency glowing

Preglowing
For vehicles except model 461 the CDI control unit (N3/9) receives the message "terminal 15 ON" via the Control Area Network bus Class C (engine compartment) (CAN-C) from the EIS [EZS] control unit (N73).
For model 461 the CDI control unit receives the signal "terminal 15 ON" discretely via the ignition/starter switch (S2/1). The CDI control unit reads the coolant temperature over the coolant temperature sensor (B11/4) and actuates the glow time output stage (N14/3) and the preglow indicator lamp (A1e16) over the local interconnect network (LIN) in response depending on the coolant temperature.
The glow time output stage then actuates the glow plugs (R9) on the plus side. The preglow indicator lamp goes out after preglowing has finished.

If an error occurs in the preglow system, at the glow plugs or on the lines then this is shown by the preglow indicator lamp and also stored in the CDI control unit.

Start-ready glowing (except model 461)
Once the preglow indicator lamp goes out then an adequately high temperature has been secured for certain running of the engine. If the CDI control unit receives the information "Circuit 50 ON" over CAN-C from the EIS [EZS] control unit it will continue to actuate the glow time output stage for a certain time irrespective of the coolant temperature which in turn actuates the glow plugs.

Start-ready glowing (model 461)
Once the preglow indicator lamp goes out then an adequately high temperature has been secured for certain running of the engine. If CDI control unit receives the signal "terminal 50 ON" discretely via the ignition/starter switch, it will continue to actuate the glow time output stage for a certain amount of time irrespective of the coolant temperature, which in turn actuates the glow plugs.

Start-up glowing (except model 461)
Start-up glowing is used to stabilize the cold start engine speed.
If the CDI control unit receives the information "Circuit 61 ON" over CAN-C from the EIS [EZS] control unit then the glow time output stage will be actuated over LIN. The glow time output stage reacts by actuating the glow plugs. In this way the first working cycles and the eventual running of the engine are supported.

Start-up glowing (model 461)
If the CDI control unit receives the information "terminal 61 ON" discretely via the ignition/starter switch then the glow time output stage will be actuated over LIN. The glow time output stage reacts by actuating the glow plugs. In this way the first working cycles and the eventual running of the engine are supported.

Afterglowing
Afterglowing improves engine running after a cold start and the engine warm-up characteristics.
After a successful engine start, the CDI control unit reads in the coolant temperature through the coolant temperature sensor and actuates the glow plugs over the glow output stage according to the coolant temperature.

Diagnostic glowing
This function ensures that the preglow indicator lamp is actuated in the instrument cluster (A1) if a fault occurs in the preheating system.

DPF glow function with code (474) Particulate filter (except model 461)
The DPF glow function is used to raise the load and to stabilize combustion and thus assists regeneration of the DPF.
The CDI control unit receives the message "Circuit 50 ON" over the CAN-C from the EIS [EZS] control unit. The CDI control unit reacts by actuating the Glow time output stage.

DPF glow function with code (474) Particulate filter (model 461)
The DPF glow function is used for increasing the load and for combustion stabilization and thus supports regeneration of the DPF.
To do this CDI control unit receives the signal "terminal 50 ON" via the ignition/starter switch. The CDI control unit reacts by actuating the Glow time output stage.

Emergency glowing
If a problem in communication occurs between the CDI control unit and the glow time output stage so that the glow time output stage does not recognize any activity 2 seconds after activation through terminal 87, the emergency glowing function is actuated for 180 seconds. If communication is missing during a glowing process for more than 250 ms then the glowing process will be continued for 180 s.

If no new glow demand is received from the CDI control unit then emergency glowing stops after 180 s.