Glow duration control
Glow duration control |
Glow duration control comprises four different sub-functions:
- |
Preheating
|
- |
Starting preparation heating
|
- |
Starting glow
|
- |
Afterglow
|
Preheating |
Depending on the temperature of the engine coolant, preheating starts when the ignition is turned to ON. At the same time, information that preheating is active is sent on the P-bus and read by the main instrument unit. This turns on the preheating indicator lamp. Preheating depends on the temperature of the engine coolant, see table.
Temperature °C (°F)
|
Duration
|
+5 (+41.0)
|
inactive
|
-10 (+14.0)
|
5 seconds
|
-20 (-4.0)
|
10 seconds
|
If the engine speed exceeds 42 rpm before the time expires, preheating will be deactivated.
Starting preparation heating |
Starting preparation heating starts after preheating if the following conditions are met:
- |
Preheating duration longer than 0 seconds
|
- |
Preheating time has expired
|
Starting preparation heating is shut off when the engine speed exceeds 42 rpm or after 30 seconds.
Starting glow |
Starting glow takes place each time the engine is started (over 42 rpm) if the engine coolant temperature is lower than 25°C (77°F). The function is deactivated if any of the following parameters are fulfilled:
- |
Starting glow duration of 2 minutes has expired
|
- |
Engine coolant temperature rises above 25°C (77°F)
|
- |
Engine speed exceeds 750 rpm (engine running)
|
Afterglow |
Once the engine has started, the control module supplies alternate pairs of glow plugs (1-3/2-4) with power.
Afterglow starts when the engine speed exceeds 750 rpm and is active as follows:
Coolant temperature °C (°F)
|
Duration
|
17 (62.6)
|
3 minutes
|
20 (68.0)
|
40 seconds
|
40 (104.0)
|
40 seconds
|
41 (105.8)
|
inactive
|
Afterglow is temporarily shut off if the engine speed exceeds 2500 rpm or if the injected fuel quantity corresponds to the value in the table.
Coolant temperature °C (°F)
|
Fuel quantity
(mg/combustion) |
40 (104.0)
|
37
|
30 (86.0)
|
40
|
10 (50.0)
|
45
|
-10 (14.0)
|
55
|
-20 (-4.0)
|
65
|
-30 (-22.0)
|
70
|
The period of afterglow continues even if it is interrupted by one of the above conditions.