Component Tests and General Diagnostics
Throttle Body Assembly On-Vehicle InspectionWARNING: Never touch throttle valve with finger while ignition switch is in ON position and accelerator pedal is depressed. Otherwise, injury may result by pinching the finger between throttle valve and throttle body.
CAUTION:
- Do not disassemble throttle body assembly.
- Do not drop or otherwise give excessive shock to throttle body assembly. Throttle body assembly that has experienced any excessive shock must be replaced.
- Be careful not to accurate foreign materials (like dust and metallic particle) to throttle body and throttle valve. Otherwise, throttle body assembly will break down by throttle valve accretion.
- Do not apply excessive force to throttle valve for throttle valve operation check and TP sensor performance check.
Otherwise, throttle body assembly will break down by damaging internal resinous gear of throttle valve actuator.
NOTE: After replacing throttle body assembly, calibrate throttle valve position.
Throttle Valve Visual Check
1. Turn OFF ignition switch.
2. Remove air cleaner assembly.
3. Check that there isn't 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 Valve Operation Check
1. Turn OFF ignition switch.
2. Remove air cleaner assembly.
3. Check throttle valve operation as follows.
If faulty condition is found, replace throttle body.
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.
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: Accelerator Pedal Position (APP) 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 motor resistance
0.3 - 100 ohms at 20 °C, 68 °F
TP Sensor (Throttle Position Sensor) Performance Check
1. Remove air cleaner assembly.
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.
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.
