Electronic control device (ECU)
It is the main component of the system, controlling the injection timing, increased idle speed, glow plugs, and the exhaust gas reburning system.
The ECU receives signals from sensors that monitor coolant temperature, engine speed, fuel injector operation, and engine load. These signals are used by the ECU to control the system.
The ECU is located in a plastic box that is mounted on the right wheel arch.
Removing
Disconnect the negative battery terminal before removing any of the fuel system components.
1. Remove the ECU cover (arrow).
2. Disconnect the electrical connector by first lifting the locking lever at the top of the connector.
3. Remove the connector from the rear, disconnect the front and remove the ECU from the pins.
4. Lift the ECU up and remove it from the box.
5. If necessary, remove the ECU box by unscrewing the inner and outer mounting bolts.
Installation
Installation is made in sequence, return to removal.
Crankshaft speed sensor
The crankshaft speed sensor is located on the front side of the clutch housing.
This is an inductive pulse generator that creates pulses when the teeth of the flywheel ring gear pass near it.
Coolant temperature sensor
The coolant temperature sensor is an NTC thermistor, meaning that as the temperature of the sensor increases, its resistance decreases.
Atmospheric pressure sensor
The atmospheric pressure sensor is located inside the ECU. This sensor is used to adjust the fuel injection timing depending on the altitude.
Absolute pressure sensor
The sensor is an integral part of the ECU and cannot be removed separately.
Bosch high pressure fuel pump load sensor
Sensor (indicated by an arrow) consists of a potentiometer whose resistance is measured depending on the position of the accelerator pedal. Based on this information, the ECU can adjust the fuel injection timing depending on the position of the pedal and the engine load.
The load sensor is installed on top of the high pressure fuel pump. Although it can be removed separately, Peugeot specific equipment is required to adjust the position of the sensor once it is in place. Therefore, this sensor must be replaced at a Peugeot station.
Nozzle needle lift sensor
The injector needle lift sensor is an integral part of one of the fuel injectors that sends a signal to the ECU when the injector opens.
Preheating control unit
This is an ECU controlled relay that connects the preheat glow plugs to the ECU for a certain amount of time when starting a cold engine.
EGR valve
The return of part of the exhaust gases to the intake manifold is controlled by the ECU in combination with the EGR solenoid valve and the EGR valve. Vacuum from the vacuum pump is directed to the EGR valve through the solenoid valve according to engine speed, load and altitude.
Examination
1. If a malfunction occurs in the system, check that all electrical connectors are connected and not oxidized.
2. Check that the air filter element is clean, the compression pressure in the engine cylinders is within normal limits and the engine ventilation hoses are not damaged.
3. If outwardly everything is in order, and there is a malfunction in the system, it is necessary to check the fuel system at a Peugeot station.
Removing
1. Trace the wiring from the sensor to the wiring connector and disconnect it from the main harness.
2. Remove the rubber sealing ring, unscrew the bolts and remove the sensor from the crankcase.
Installation
Installation is made in sequence, return to removal.
Control cable and diaphragm
Removing
1. For better access, remove the air intake from the front of the engine.
2. Mark the position of the control cable relative to the lever and disconnect the cable from the high pressure fuel pump.
3. Remove the vacuum hose (A) from diaphragm assembly (B - bracket mounting bolts).
4. Release the cable from the mounting brackets, unscrew the 2 bracket mounting bolts and remove the bracket from the exhaust manifold.
Installation
1. Installation is made in sequence, return to removal.
2. Adjust high idle.