Contents: Fuel temperature sensor ↓ Boost pressure sensor ↓ Checking the supply voltage ↓ Checking the boost pressure sensor ↓ Intake Air Temperature Sensor ↓ Engine Coolant Temperature Sensor ↓ Crankshaft position sensor ↓ Rotation speed sensor (fuel…↓ Correction resistors of…↓ Control system relay ↓
Fuel temperature sensor
Note: On some early models the sensor is missing and a plug is installed in its place.
1. Verification
a) Turn off the ignition.
b) Disconnect the fuel temperature sensor connector.
c) Place a container under the high-pressure fuel pump to collect the fuel.
d) Remove the fuel temperature sensor.
d) Immerse the sensitive element of the fuel temperature sensor in water of known temperature.
e) Measure the resistance between the terminals of the fuel temperature sensor at the test points.
Connector color - Dark gray
Temperature - Resistance
20°C — ~2500 Ohm
40°C — ~1100 Ohm
60°C — ~600 Ohm
80°C — ~300 Ohm
Fig. 16 Checking the fuel temperature sensor
Boost pressure sensor
Connected by a rubber tube to the intake manifold. The pressure in the intake manifold of a turbocharged engine varies from a vacuum of about 100 mm Hg at idle to an excess pressure of 0.98 bar at full load and with the turbine on.
Marking:
- SENSOR ASS/
- TURBO PRESSURE
- Manufacturer — TOYOTA
- Connector color - Black
Checking the supply voltage
1. Turn off the ignition.
2. Disconnect the boost pressure sensor connector.
3. Turn on the ignition.
4. Measure the voltage between the connector terminals.
Terminal - purpose
1. E2 - "ground"
2. R/M - sensor signal
3. VC - +5V power supply
Terminals - voltage
VC and E2 - 4.5-5.5 V
Fig. 17 Checking the boost pressure sensor
Checking the boost pressure sensor
1. Turn off the ignition.
2. Remove the vacuum tube from the boost pressure sensor.
3. Provide access to the sensor connector terminals without disconnecting the connector.
4 Turn on the ignition.
5 Measure the voltage between the "PIM" and "E2" terminals of the connector.
6 Compare with the voltage according to technical specifications.
7. Use a vacuum pump to create a vacuum on the sensor.
8 Measure the voltage between the connector terminals.
Vacuum - Voltage Drop
100 mm Hg - 0.3 - 0.5 V
200 mm Hg - 0.6 - 0.8 V
300 mmHg — 0.95 - 1.15 V
9. Compare the voltage drop with the technical specifications.
10. Apply excess pressure to the sensor.
11. Measure the voltage between the connector terminals.
Pressure - increase in tension
0.19 bar - 0.4-0.7 V
0.39 bar - 0.9- 1.2 V
0.59 bar - 1.4- 1.7 V
0.79 bar - 2.0-2.3 V
0.98 bar - 2.5-2.8 V
12. Compare the voltage increase with the technical specifications.
Voltage between terminals "PIM" and "E2" of the connector with the engine running
PIM and E2 terminals
Operating mode - Voltage
Warm-up - 1.4 V
Idle speed - 0.8 V
at 3000 rpm - 1.5 V
Fig. 18 Checking the boost pressure sensor
Intake Air Temperature Sensor
The air temperature sensor measures the air temperature after the air cleaner for subsequent calculation of the volume of air entering the engine cylinders and sending a command to inject the corresponding amount of fuel. Always works in tandem with the absolute air pressure sensor in the intake manifold. Installed in the intake air duct on the rear side of the air cleaner
Two-pin connector without marking. Color black
Purpose - Wire Color
brown - "earth"
yellow - signal
Resistance check
1. Turn off the ignition.
2. Disconnect the sensor connector.
3. Measure the ambient air temperature.
4. Measure the resistance between the sensor terminals.
Temperature - Resistance
20°C — ~2500 Ohm
40°C — ~1100 Ohm
60°C — ~600 Ohm
80°C — ~300 Ohm
Fig. 19 Checking the resistance of the intake air temperature sensor.
Engine Coolant Temperature Sensor
The sensor is located on the thermostat.
Examination
1. Turn off the ignition.
2. Disconnect the sensor connector.
3. Release residual pressure in the cooling system.
4. Remove the sensor from the engine.
5. Immerse the sensitive element of the sensor in water with a known temperature.
6. Measure the resistance between the sensor terminals at the test points.
Connector color - Gray
Temperature - Resistance
20°C — ~2500 Ohm
40°C — ~ 1000 Ohm
60°C — ~ 600 Ohm
80°C — ~300 Ohm
On a warmed-up diesel engine, the voltage on the sensor is ~ 7 V
Fig. 20 Checking the coolant temperature sensor.
Crankshaft position sensor
It also serves as a crankshaft speed sensor. It is located on the block next to the flywheel in the lower part of the crankcase.
Connector color - Black
Resistance (cold engine) — 19 - 32 Ohm
(warm engine) — 24 - 37 Ohm
Resistance check
1. Turn off the ignition.
2. Disconnect the sensor connector.
3. Measure the resistance between the sensor terminals
Fig. 21 Checking the resistance of the crankshaft position sensor
Rotation speed sensor (fuel injection pump shaft positions)
It is installed in the fuel injection pump. In some diagrams it is also designated as the engine speed sensor. This is possible because in essence it is also the fuel injection pump speed sensor, which is unambiguous to the engine speed.
The sensor is installed in the front part of the fuel injection pump from above vertically
Connector - white
Temperature - Resistance
20°C — 205-255 Ohm
Resistance check
1. Turn off the ignition.
2. Disconnect the sensor connector.
3. Measure the resistance between the sensor terminals.
Fig. 22 Rotation speed sensor (injection pump shaft position sensor)
Correction resistors of high-pressure fuel pump
Resistance check
1. Turn off the ignition.
2. Disconnect the connector of each resistor in turn.
3. Measure the resistance between the resistor terminals.
Temperature - Resistance
20°C — 100 - 2500 Ohm
Fig. 23 Checking fuel injection pump resistors
Control system relay
Checking the work
Note: Please observe the polarity of power supply connection, otherwise the relay may be damaged.
1. Turn off the ignition.
2. Remove the relay.
3. Measure the resistance between terminals 3 and 4 of the relay.
4. Connect power from the battery to the indicated terminals (1 and 2) of the relay.
5. Measure the resistance between terminals 3 and 4 of the relay.
Changeover contact terminals
Z and 4
Power - Resistance
no - infinity
there is - zero
(Battery positive to terminal 1)
(Battery negative to terminal 2)
Fig. 24 Checking the control relay