General Information QOS - III
The QOS - III preheating system consists of the ignition and starter switch, a QOS - III controller, two glow relays, a pre - resistor, a coolant temperature switch and the vehicle speed sensor.
The QOS - III system uses two relays, relay 1 for pre - heating and relay 2 for afterglow. In the case of afterglow the power to the glow plugs is submitted through a pre - resistor. The relays are activated in the following way:
Ignition "ON"
Glow relay 1 is activated. Depending on the coolant temperature the pre - heating time is 1.4 to 13 seconds. When the engine is not started within this time glow relay 1 will be deactivated and will be activated when the engine is started or when the ignition is switched "OFF" and "ON" again.
The indicator light comes on for 1.4 to 5 seconds depending on the coolant temperature. Glow relay 2 is not activated.
Ignition and starter key in position "START"
When the ignition and starter switch is turned to the "START" position both relays are activated.
Glow relay 1 is activated for 1.4 to 13 seconds depending on the engine temperature. Glow relay 2 is activated for 3 minutes regardless of engine temperature, this only when the engine temperature is below the 70 °C / 158 °F. Above this temperature glow relay 2 will not be activated.
The count down starts at the moment the key is in the "START" position.
If the engine will not run both glow relays are deactivated at the moment the ignition and starter switch is returned to the "ON" position.
If the vehicle reaches a speed of 18 km / h / 11 mph during the afterglow, glow relay 2 is deactivated until the speed drops below 9 km / h / 5 mph. This is when the time after start is shorter than 3 minutes.