The engines installed on Renault/Dacia Sandero vehicles are equipped with an electronic engine management system with multiport fuel injection.
This system ensures that the latest emissions and fumes standards are met while maintaining high driving performance and low fuel consumption.
The cars are equipped with a feedback engine control system (the presence of a catalytic converter and an oxygen concentration sensor).
We remove the sensors and the electronic engine control unit for inspection, as well as for replacement.
Removing the electronic engine control unit
We prepare the car for the task, disconnect the negative battery terminal
With a 10 socket head, unscrew the two nuts securing the computer
Pull out the latch in the direction shown by the arrow
Disconnect the wiring block and remove the electronic unit
Install parts in reverse order
Replacing the crankshaft speed sensor
If the crankshaft sensor fails, the engine stops working.
In the instrument cluster, a signal lamp lights up and the controller stores a fault code in memory.
Using a screwdriver, we press the lock of the wire block
Disconnecting the sensor wiring harness block
Using a 10 key, we unscrew the two sensor mounting bolts
Remove the sensor
Install the sensor in reverse order.
After replacing the crankshaft sensor or flywheel, you need to make sure that the fuel injection system is working correctly using a special tool.
Verification includes the following:
- - deceleration of the car with a cut in the fuel supply in II, III, IV or fifth gear at a speed of 3500-3000 min -1 for at least 2s;
- - repeated deceleration with fuel supply interruption in II, III, IV or fifth gear at a speed of 2400-2000 min -1 for at least 3 s;
- - check for fault codes and, if necessary, troubleshoot;
- - erase codes.
Replacing the coolant temperature sensor
The coolant temperature sensor is installed in the cylinder head near the first cylinder.
The sensor is a thermistor, as the temperature increases, the resistance of the sensor decreases.
Depending on the sensor signal, the optimal value of the mixture enrichment is set.
To remove and test the sensor, you will need a 21 wrench, a flat-blade screwdriver, a tester, a thermometer.
Disconnect the negative battery terminal
Drain the coolant (article - Replacement and engine coolant Renault Sandero)
We press the clamp of the sensor wiring harness block
Disconnect the wiring harness from the coolant temperature sensor
Loosen the sensor with a wrench and unscrew it by hand
Install the parts in reverse order.
Pour coolant into the engine cooling system.
Replacing the throttle position sensor
The sensor is a potentiometer that is mounted on the throttle shaft.
Rotation of the throttle axis changes the voltage of the sensor signal, by which the electronic unit determines the degree of throttle opening.
If there is a problem with the engine idling or a deterioration in throttle response, check the sensor and its connector.
To remove the sensor, you will need a Torx T20 key, tester
Disconnect the negative battery terminal
Remove the air filter (article - How to replace the Renault Sandero engine air filter element)
We press the latch and disconnect the wire block from the sensor
Connect the tester to terminals "B" and "C" of the sensor in resistance measurement mode
Measure the resistance at the terminals with the throttle fully closed.
It should be 2.3-2.4 kOhm.
Turn the throttle by hand until it is fully open and measure the resistance again.
Resistance should be 1.3-1.4 kOhm.
To replace the sensor, unscrew the two mounting bolts
Remove the throttle position sensor
Install the sensor in reverse order.
Replacing the absolute pressure (vacuum) sensor in the intake pipe
The sensor detects the change in pressure (vacuum) in the intake pipe depending on the engine speed and converts it into an output signal voltage.
Depending on the sensor signal, the controller calculates the amount of air entering the engine.
Disconnect the negative battery terminal
Press the wire block retainer
Disconnect the wiring harness from the sensor
Remove the sensor (the sensor fitting is installed with an interference fit in the intake pipe hole)
Install the sensor in reverse order
Replacing the air temperature sensor in the intake pipe
The sensor is an NTC thermistor (the electrical resistance of the sensor decreases with increasing temperature).
The ECU regulates the amount of injected fuel depending on the signal from the sensor.
On the K4M engine, the air temperature sensor is mounted on the receiver and removed as well
Disconnect the negative battery terminal
Remove the air filter (article - How to replace the Renault Sandero engine air filter element)
Disconnect the wiring harness block from the sensor by squeezing the spring clip with your fingers
Pry off the sensor with a screwdriver
Remove the sensor from the intake manifold
Install the sensor in reverse order
Removing and installing knock sensor
The knock sensor is installed between the second and third cylinders.
The sensor detects vibrations, shocks in the engine.
We install the car on a lift or a viewing ditch
Disconnect the negative battery terminal
Squeeze the latch and disconnect the wire block from the sensor
Use a 24 key to unscrew the knock sensor
And remove the sensor.
Install the parts in reverse order.
Replacing the control sensor for oxygen concentration in exhaust gases
The sensor is installed on the exhaust manifold.
The sensor measures the amount of oxygen in the exhaust gases and converts the measured value into a signal voltage that is supplied to the controller.
Using the signals from the sensor, the ECU controls the fuel injection in such a way as to obtain the calculated composition of the fuel mixture.
The oxygen concentration sensor is a key component m exhaust gas cleaning system, you need to use only high-quality spare parts.
Disconnect the negative battery terminal
Press the wire block retainer
Disconnecting the wire block
Remove the block from the bracket by sliding it forward
Unscrew the three nuts securing the thermal screen
Remove the thermal screen
Remove the wire from the holder
Weaken the sensor with the key 22
Unscrew the sensor from the exhaust manifold
Install the sensor in reverse order. Sensor tightening torque 40-60 Nm.
Sensor threads should be lubricated with graphite grease.
Removing the diagnostic oxygen sensor
The diagnostic sensor is installed after the catalytic converter.
The sensor works on the same principle as the control sensor.
The signal generated by the diagnostic oxygen sensor indicates the presence of oxygen in the exhaust gases after the converter.
If the converter is working properly, the readings of the diagnostic sensor will differ significantly from the readings of the control sensor.
Disconnect the block of wires by pressing the latch
Weaken the sensor with the key 22
Unscrew the sensor
Install the sensor in reverse order
Removing the vehicle speed sensor
The speed sensor is mounted on the gearbox and is a Hall effect sensor.
The sensor sends a pulse signal to the ECU proportional to the speed of the drive wheels.
We press the lock of the sensor wire blocka
Disconnect the wiring harness from the speed sensor
Pry off the sensor with a screwdriver
Remove the sensor from the gearbox housing.
Install the sensor in reverse order.