Accelerator pedal sensor
The spindle which is connected to the accelerator pedal operates the position sensor. The sensor comprises a carbon strip and a stylus, the spindle operates the stylus. The stylus moves over the carbon strip, the voltage on the stylus depends on the position at which the stylus touches the carbon strip. Based on the output voltage the control unit determines fuel
Quickcheck
Check connector(s): Inspect the connector(s) and if necessary clean or fix them to make sure the connection is good. Check supply voltage accelerator pedal position sensor: Turn off ignition. Remove connector from pedal position sensor. Turn ignition on. Measure voltage between supply terminal and the negative terminal of the battery. It should equal specified voltage. If not check wiring then check ECU. Check connection to ECU: Turn off ignition. Remove connector from pedal position sensor and ECU. Measure the resistance between connectors terminal and the corresponding terminal in the ECU connector. Should be < 1 ohm. If not check wiring. Check position sensor signal: Connect oscilloscope to the signal wire pin of the ECU and ground. Turn ignition on and compare to the data.
Air temperature sensor
Function
The air temperature sensor incorporates a NTC thermistor, the resistance decreases as the temperature of the air increases. As the temperature changes, the thermistor resistance changes, enabling the control unit to calculate the air temperature from the level of voltage that is registered on the sensors' signal wire.
Quickcheck
Check connector(s): Inspect the connector(s) and if necessary clean or fix them to make sure the connection is good. Check resistance: Turn off ignition. Remove connector from sensor. Measure resistance between pins of the sensor. Compare with specified resistance. Check supply voltage: Turn off ignition. Remove connector from sensor. Turn ignition on and measure successively voltage between connector terminal and the negative terminal of the battery. One should be 5 V. If not check wiring then check ECU. Check connection to ECU: Turn off ignition. Remove connectors from sensor and ECU. Measure the resistance between supply voltage connector terminal and the corresponding terminal in the ECU connector. It should be 1 ohm. If not check wiring. Check ground: Check in schematic if ground connection is connected to a direct ground or to the ECU. When it is connected directly to ground: Turn off ignition. Remove connector from sensor and measure resistance between ground connector terminal and the negative terminal of the battery. It should be < 1 ohm. If not check wiring. When it is connected to the ECU: Turn off ignition. Remove connector from sensor and ECU. Measure resistance between ground connector terminal and the corresponding terminal in the ECU connector. It should be < 1 ohm. If not check wiring then check ECU.
Boost pressure valve
Function
The solenoid controls a valve which opens or closes the air line between the waste gate valve and vacuum. When the valve opens vacuum is applied to the waste gate valve, which in turn regulates the amount of exhaust gasses passing through the exhaust gas turbine. In this way the turbo pressure is regulated.
Quickcheck
Check connector(s): Inspect the connector(s) and if necessary clean or fix them to make sure the connection is good. Check resistance: Turn off ignition. Remove connector from solenoid. Locate the two pins of the solenoid. Measure resistance between the two pins of the solenoid. Compare with specified resistance. Alternatively you can check functioning of the solenoid by applying battery voltage to the two pins of the solenoid, the solenoid should "click". Check supply voltage: Turn off ignition. Remove connector from solenoid. Locate the two connector terminals of the solenoid. Start the engine and measure voltage between one connector terminal of the solenoid and the negative terminal of the battery. Check the second terminal of the solenoid, one of the two should equal the battery voltage. If not check wiring and if present fuse and relay. Check connection to ECU: Turn off ignition. Remove connectors from solenoid and ECU. Locate the two connector terminals of the solenoid. Measure the resistance between one of the two connector terminals of the solenoid and the corresponding terminal in the ECU connector. Check the other terminal of the solenoid, one of the two should be < 1 ohm. If not check wiring.