Fig. 3.20. Location of various engine management system components and wiring harnesses in the engine compartment with the G8T 714 engine: 1 - Engine control unit; 2 - engine warm-up control unit; 3 - inertial shock sensor; 4 - fuel heater temperature sensor; 5 - Electric fuel heater; 6 - acceleration sensor; 7 - EGR electromagnetic valve; 8 - coolant temperature sensor; 9 - coolant temperature indicator in the instrument cluster; 10 - air temperature sensor; 11 - speed sensor; 12 - crankshaft speed and position sensor; 13 - Reverse light switch; 14 - electromagnetic valve of fast idle speed; 15 - air conditioning system temperature sensor; 16 - Fuel injector needle lift sensor connector
Fig. 3.21. Location of various engine management system components and wiring harnesses in the engine compartment with the G8T 716 engine: 1 - Engine control unit; 3 - inertial shock sensor; 4 - fuel heater temperature sensor; 5 - Electric fuel heater; 7 - EGR electromagnetic valve; 8 - coolant temperature sensor; 9 - coolant temperature indicator in the instrument cluster;10 - air temperature sensor; 11 - speed sensor; 12 - crankshaft speed and position sensor; 13 - Reverse light switch; 14 - electromagnetic valve of fast idle speed; 15 - air conditioning system temperature sensor
The pre-heating and post-heating function is controlled by an electronic unit.
The glow plug relay unit is integrated into the electronic control unit.
Turn on preheating
Preheating is carried out in two phases:
- a) variable preheating - depends on the temperature of the coolant at the moment the ignition is turned on (Fig. 3.22).
- b) Continuous preheating. After the preheating indicator lamp (variable preheating) goes out, voltage is supplied to the glow plugs for another 8.5 seconds before the engine starts.Starting the engine
Fig. 3.22. Dependence of the engine preheating activation time on the coolant temperature in the variable preheating mode
When the engine crankshaft is turned by the starter, power is supplied to 4 glow plugs
Post-heating after engine start
Subsequent heating is carried out in two phases:
Information is located on the website: www.RenaultBook.ru
- a) continuous post-heating. After the engine has started, voltage is supplied to the glow plugs for another 10 seconds.
- b) Variable post-heating. Variable post-heating starts when constant post-heating ends. The voltage supply time to the glow plugs is 3 min.
Post-heating can be interrupted permanently if the coolant temperature has exceeded 60°C or temporarily if the control unit receives a 60% load signal from the potentiometer for more than 3 seconds. In this case, the function is restored when switching to idle or low load mode.
Fig. 3.23. Dependence of engine preheating on-time on coolant temperature in variable post-heating mode