The spark plug used in this vehicle is self-regulating.
For this purpose, in addition to the heating coil, the spark plug has a control coil, which is connected in series with the heating coil and serves to limit the current and stabilize the temperature of the spark plug as it warms up due to the increase in resistance of the control coil.
Control parameters of the glow plug preheating system
| Control parameter | Normal value |
| Resistance between glow plug body and positive contact (at 20°C) for parallel connection of 4 glow plugs | 0.15-0.25 Ohm |
| Voltage on the spark plug immediately after turning on the ignition (without turning on the starter) | 9-11 V (drops to 0 V after 4-8 sec, which means the end of preheating) |
| Voltage on the spark plug when the engine is turned by the starter | Not less than 6 V |
| Voltage on the spark plug after starting the engine | 12-15 V (drops to 0 V after warming up to 60°C or after 180 seconds from engine start) |
| Resistance of the relay electromagnet at 20°C on contacts C and E (see Fig. M2 2.184) | 18-22 Ohm |
| Resistance of one spark plug at 20°C | 0.6 -1.0 Ohm |
Glow plug operating modes
Preheating before starting
Activated when ignition is turned on Engine temperature: from 60°C and below. Maximum warm-up time: about 10 sec.
The indicator light is on.
Post-start warm-up
Used to align the operation of engine cylinders.
Engine temperature: from 60°C and below. Maximum warm-up time: about 180 sec.
Engine speed: not less than 360 rpm.
The starter is off.
The indicator light does not light.