Functions of the injection ECU
- Checking the operation and stopping of the cooling fan (engine cooling)
- To control the piloted thermostat
- Control of the post ventilation
- To control the lighting of the stop warning lamp on the instrument panel
- Control of the coolant temperature logometer on the instrument panel
- Fan operation diagnostics
- Acquisition of the engine coolant temperature
- To manage the back-up modes
Flow chart
Key
- Single arrow: wire connection
- Triple arrow: multiplexed connection
- (*) EW10A engine (PEUGEOT 307 and 807 - "Full CAN")
| designation | part number in the electrical diagrams |
|---|---|
| built-in systems interface | BSI1 |
| instrument panel | 0004 |
| engine coolant temperature sensor | 1220 |
| Air intake temperature sensor | 1312 |
| injection ECU | 1320 |
| piloted thermostat | 1380 |
| fan | 1510 |
| variable speed cooling fan | 1513 |
| automatic gearbox | 1630 |
| ESP ECU | 7800 |
| external temperature sensor | 8032 |
| front right hand door station | 9050 |
| connection number | transmitter/receiver | signal | nature of signal |
|---|---|---|---|
| 1 | 1220/1320 | engine coolant temperature information | analogue |
| 2 | 1312/1320 | inlet air temperature information | analogue |
| 3 | 1320/1380 | control of the piloted thermostat resistor | OCR: opening cyclic ratio |
| 4 | 1513/1320 | status of the variable speed cooling fan | analogue |
| 5 | 1320/1513 | control of the cooling fan | analogue |
| 6 | 1320/1510 | control of the cooling fan | analogue |
| 7 | 1510/1320 | cooling fan status | analogue |
| 8 | 1630/1320 | cooling requirement information | CAN |
| 9 | 7800/1320 | vehicle speed information | CAN |
| 10 | 1320/0004 | engine coolant temperature information | CAN |
| "STOP" warning lamp lighting request | |||
| 11 | 9050/1320 | exterior air temperature information | COMFORT CAN |
| 12 | 8032/9050 | exterior air temperature information | analogue |
| 13 | 1320/0004 | coolant temperature indicator | COMFORT CAN |
| control of the lighting of the stop warning lamp |
Electric cooling fan unit
Engines EW7A and EW10A are equipped with a cooling fan piloted by electronic chopper (PEUGEOT 407)
The EW10A engine is fitted with a dual speed fan (PEUGEOT 307 and 807 - "Full CAN")
The engine cooling fan is triggered in relation to the coolant temperature and the control of the piloted thermostat
NoteThe command for opening the piloted thermostat is determined by the vehicle speed, the inlet air temperature, the ambient air temperature, engine load and the engine coolant temperature
Example of the cooling fan unit reference speed in relation to the engine coolant temperature and the open cycle ratio of the piloted thermostat for the "Full CAN" 807
| engine coolant temperature | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| open cycle ratio of the piloted thermostat (in %) | 97 | 99 | 101 | 103 | 105 | 107 | 109 | 110 | 113 |
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 50 | 100 |
| 10 | 0 | 0 | 0 | 0 | 0 | 0 | 50 | 100 | 100 |
| 20 | 0 | 0 | 0 | 0 | 0 | 0 | 50 | 100 | 100 |
| 30 | 0 | 0 | 0 | 0 | 0 | 0 | 100 | 100 | 100 |
| 40 | 0 | 0 | 0 | 0 | 0 | 50 | 100 | 100 | 100 |
| 50 | 0 | 0 | 0 | 0 | 0 | 50 | 100 | 100 | 100 |
| 60 | 0 | 0 | 0 | 0 | 0 | 100 | 100 | 100 | 100 |
| 70 | 0 | 0 | 0 | 0 | 50 | 100 | 100 | 100 | 100 |
| 80 | 0 | 0 | 0 | 50 | 100 | 100 | 100 | 100 | 100 |
| 90 | 0 | 0 | 50 | 100 | 100 | 100 | 100 | 100 | 100 |
| 100 | 0 | 50 | 50 | 100 | 100 | 100 | 100 | 100 | 100 |
Key
- 50 %: slow speed
- 100 %: high speed
Engine coolant temperature sensor (1220)
The coolant temperature sensor informs the injection ECU of the temperature of the engine coolant
Piloted thermostat
"a" connector
(14) piloted thermostat
Role
The piloted thermostat permits
- The engine temperature to rise more rapidly for better control of the exhaust gas depollution
- A higher engine temperature for reduced friction and therefore improved fuel consumption
Description
A: thermostat open (piloted or not piloted if the temperature is above 105°C)
B: thermostat closed
(15) wax
(16) heated resistor
The wax contained in the piloted thermostat melts at a temperature of 105°C
During normal operation, the thermostat is not piloted, it regulates the coolant temperature at 105°C
For full loads, the injection ECU controls the regulation of the thermostat at 89°C
The injection ECU controls the piloted thermostat heated resistor (16) in order to add the 16°C which are lacking to the 89°C of the coolant to melt the wax (15)
Piloted thermostat operating phase
Key
- C: partial load
- D: full load
- T (°C): engine coolant temperature
- T: time
| time | operating phase | description of the operating phase |
|---|---|---|
| t0 and t1 | partial load | the injection ECU does not activate the piloted thermostat regulation control. the engine coolant temperature is regulated at 105°C guaranteeing a reduction in consumption. |
| t1 and t2 | full load | the injection ECU detects a full engine load and controls the opening of the piloted thermostat by means of the internal resistor which melts the wax, simulating a temperature of 105°C. the engine coolant temperature decreases and stabilises at a temperature of 89°C |
| t2 and t3 | full load | the engine cooling is regulated at an engine coolant temperature of 89°C in order to avoid an excessively high engine operating temperature |
| t3 | partial load | the injection ECU detects a partial load and no longer controls the activation of the piloted thermostat internal resistor. the piloted thermostat again regulates at the engine coolant temperature of 105°C |
The operation of the piloted thermostat is also determined as a function of the following parameters
- The vehicle speed and the inlet air temperature, guaranteeing the performance of the engine cooling
- The ambient air temperature, ensuring that the temperature under the bonnet is correct in cold weather and is not adversely affected in hot climates
NoteThe automatic gearbox cooling requirement has priority over the other cooling requests. when the automatic gearbox makes a cooling request, the regulation of the piloted thermostat is 89°C
WarningBleeding of the cooling system uses a special injection ECU strategy. in order to inform the injection ECU of entry into a cooling system bleed phase, the following conditions must be fulfilled for 10 seconds: vehicle speed zero, engine speed above 1450 rpm, engine torque below 50 N.m
Cooling system
(14) piloted thermostat
(17) heater matrix
(18) coolant outlet housing
(19) cooling radiator
(20) coolant/engine oil exchanger
(21) expansion chamber
(22) motor
(23) coolant inlet manifold
(24) by-pass
Post ventilation
The parameters of the cooling fan triggering map are set by the coolant temperature and the exhaust line temperature sensor
Depending on the energy stored by the catalytic converter, the cooling fan is triggered at low or high speed
Back-up mode
Role of the injection ECU if the coolant temperature sensor is faulty
- To control operation of the fan at high speed
- To control the lighting of the stop warning lamp on the instrument panel
- Prohibiting of control of the air conditioning compressor (AC/OUT)