Throttle Body: Testing and Inspection
Electric 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.
Throttle Valve Visual Check
1) Turn OFF ignition switch.
2) Remove air cleaner assembly. Air Cleaner Assembly Removal and Installation
3) Check that there isn't any foreign matter caught between throttle valve and throttle body housing. 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) Move throttle valve with finger to its full open position and check that it moves smoothly.
4) Move throttle valve with finger to its completely closed position and check that it moves smoothly.
5) Take off finger from throttle valve (1) which is at full open position and check that it moves smoothly by its return spring and open spring force back to default position (position where throttle valve is open by 7° (2) from completely closed position).
6) Take off finger from throttle valve (1) which is at completely closed position and check that it moves smoothly by its return spring and open spring force back to default position.
If check result is not satisfactory, replace electric throttle body assembly.
Electric Throttle Body Assembly Operation Check
1) Remove air cleaner outlet hose.
2) Turn ON ignition switch.
3) Depress accelerator pedal gradually and check that throttle valve moves smoothly until it opens fully.
4) Release accelerator pedal depressed in Step 3) and check that throttle valve (1) moves back to default position (position where throttle valve is open by 7° (2) from its completely closed position).
If check result is satisfactory, electric throttle body system is in good condition. If check result is not satisfactory, proceed to next step.
5) Perform "Accelerator Pedal Position (APP) Sensor Assembly On-Vehicle Inspection", "Throttle Actuator (Motor) Check" and "Throttle Position Sensor Performance Check".
If check results are not satisfactory, replace electric throttle body assembly.
If check results are satisfactory, wire circuit and/or ECM are faulty.
Throttle Actuator (Motor) Check
1) Turn OFF ignition switch.
2) Disconnect connector from electric throttle body assembly.
3) Measure resistance between "M1" terminal (1) and "M2" terminal (2) of electric throttle body assembly.
If measured resistance is out of specified value, replace electric throttle body assembly.
Throttle actuator (motor) resistance
0.3 - 100 ohms at 20 °C, 68 °F
Throttle Position (TP) Sensor Performance Check
1) Turn OFF ignition switch.
2) Remove air cleaner assembly. Air Cleaner Assembly Removal and Installation
3) Disconnect connector from electric throttle body assembly.
4) Check TP sensor (main and sub) output voltage as the following steps.
a) For TP sensor (main), arrange 3 new 1.5 V batteries (1) in series (check that total voltage is 4.5 - 5.0 V) and connect its positive terminal to "Vin" terminal (2) and negative terminal to "Ground" terminal (3) of sensor. Then using voltmeter, connect positive terminal to "Vout 1" terminal (4) of sensor and negative terminal to battery.
b) For TP sensor (sub), arrange 3 new 1.5 V batteries (1) in series (check that total voltage is 4.5 - 5.0 V) and connect its positive terminal to "Vin" terminal (2) and negative terminal to "Ground" terminal (3) of sensor. Then using voltmeter, connect positive terminal to "Vout 2" terminal (4) of sensor and negative terminal to battery.
c) Measure output voltage variation while throttle valve is opened and closed as the following specification.
