Throttle Body: Testing and Inspection
Throttle Body Assembly On-Vehicle Inspection
CAUTION:
If you touch the throttle valve with your finger when the ignition switch is in the "ON" position and the accelerator pedal is depressed, your finger may be pinched in the gap between the throttle valve and throttle body housing if the accelerator pedal is released.
Never touch the throttle valve with your finger when the ignition switch is ON and the accelerator pedal is depressed.
NOTE:
Failure to take proper precautions when handling the electric throttle body assembly, may lead to malfunction of the electric throttle body assembly or damage to its components.
- Do not disassemble the electric throttle body assembly.
- Do not drop or otherwise expose the electric throttle body assembly to large shock. Any electric throttle body assembly that has received large shock should be replaced.
- Keep the throttle body housing and/or throttle valve free of dust, metallic particles or other foreign materials.
- Do not apply undue forces to the throttle valve when checking operation of the throttle valve or performance of the TP sensor; otherwise the plastic gears in the throttle valve actuator will be damaged.
NOTE:
After replacing throttle body assembly, calibrate throttle valve position. Testing and Inspection
Throttle Valve Visual Check
1) Turn OFF ignition switch.
2) Remove air cleaner assembly. Air Cleaner Assembly Removal and Installation
3) Check that there is not any foreign matter caught between throttle valve and throttle body. If there is, take it out after removing throttle body and clean inside of throttle body thoroughly. Throttle Body Assembly Removal and Installation
Throttle Valve Operation Check
1) Turn OFF ignition switch.
2) Remove air cleaner assembly. Air Cleaner Assembly Removal and Installation
3) Check throttle valve operation as follows.
If faulty condition is found, replace throttle body. Throttle Body Assembly Removal and Installation
a) Check that throttle valve (1) moves smoothly from fully closed position and fully open position with finger.
b) Check that throttle valve returns off to default position when you move finger off throttle valve at fully closed position and fully open position.
Throttle valve default position "a":
7° from completely closed position (1)
Throttle Body System Operation Check
1) Remove air cleaner assembly. Air Cleaner Assembly Removal and Installation
2) Turn ignition switch to ON position.
3) Check throttle body system as follows.
If faulty condition is found, go to step 4).
a) Depress accelerator pedal gradually and check that throttle valve moves smoothly until it opens fully.
b) Release accelerator pedal and check that throttle valve moves back to default position.
Throttle valve default position "a":
7° from completely closed position (1)
4) Check the following.
If check results are satisfactory, replace throttle body assembly.
- Wire harness and connections
- APP sensor: APP (Accelerator Pedal Position) Sensor Inspection
- TP sensor:
- Throttle motor:
Throttle Motor Check
1) Turn OFF ignition switch.
2) Disconnect connector from throttle body assembly.
3) Measure resistance between terminals "5" and "6" of throttle body assembly.
If faulty condition is found, replace throttle body assembly. Throttle Body Assembly Removal and Installation
Throttle motor resistance
0.3 - 100 ohms at 20 °C, 68 °F
TP Sensor (Throttle Position Sensor) Performance Check
1) Remove air cleaner assembly. Air Cleaner Assembly Removal and Installation
2) Turn OFF ignition switch.
3) Disconnect connector from throttle body assembly.
4) Check TP sensor (main and sub) output voltage as follows.
If faulty condition is found, replace throttle body. Throttle Body Assembly Removal and Installation
a) Connect 3 new 1.5 V batteries (1) in series and check that total voltage is 4.5 - 5.0 V.
b) Connect voltmeter (2) and batteries to TP sensor as shown in figure.
c) Check that voltage varies depending on throttle opening angle as shown in figure while throttle valve is opened and closed by finger.
