Throttle position sensor test (TPS)
The throttle position sensor is a sliding contact potentiometer that moves according to the rotation of the throttle shaft, indicating the opening angle of the throttle. When the throttle axis is rotated, the signal voltage of the throttle position sensor changes. Based on the change in the voltage value of the sensor signal and the rate of its change, the electronic engine control unit determines the degree and speed of opening the throttle.
Checking the automatic transmission oil temperature sensor
Pic. 3.52. Scheme for checking the automatic transmission oil temperature sensor
Remove the automatic transmission oil temperature sensor.
Measure the resistance between terminals 1 and 2 of the sensor connector at the test points.
Checking the vehicle speed sensor (vehicle speed sensor)
Pic. 3.53. Vehicle speed sensor test circuit
Remove the vehicle speed sensor and connect a resistance of 3–10 kOhm to it, as shown in Figure 3.53.
By rotating the shaft of the vehicle speed sensor, make sure that voltage appears on terminals 2–3 of the sensor connector (4 pulses per revolution).
Checking the automatic transmission control relay (a/t control relay)
Pic. 3.54. Automatic transmission control relay test circuit
Remove the automatic transmission control relay.
With wire connector «crocodile» (jumper wires) connect terminal 2 of the automatic transmission control relay with positive (+) battery terminal, and pin 4 - with a negative (–) terminal.
Check the condition of the circuit between terminals 1 and 3 of the control relay with the wires connected and disconnected from the battery terminals.
If relay operation is not as specified, replace the automatic transmission control relay.
Checking the solenoid valves
Pic. 3.55. Solenoid Valve Test Diagram
Remove the control valve body cover.
Disconnect the connectors for each solenoid valve.
Pic. 3.56. Resistance measurement between terminals 1 and 2 of each solenoid valve
Measure the resistance between terminals 1 and 2 of each solenoid valve (pic. 3.56).
If the resistance is out of specification, replace the solenoid valve.
Pic. 3.57. Control Valve Block Connector Pinouts
Note. Resistance at the terminals of the control valve block connector (pic. 3.57).