Electronic Throttle Actuator Position Sensor: Testing and Inspection
Angle Sensor -1- For Throttle Drive, Checking
Special Tools and Equipment
- VAG1526A
- VAG1594A
- VAG1598/31
- VAS5051 with VAG5051/1
or
- VAG1551 with VAG1551/3B
Angle sensor 1 for throttle drive (power accelerator actuation) -G187- and angle sensor 1 for throttle drive (power accelerator actuation) -G188- inform the Engine Control Module (ECM) about the position of the throttle valve. Both angle sensors are located in the throttle valve control module.
Test Sequence
- Connect VAS5051 tester or VAG1551 scan tool and select the control module for engine electronics using "address word" 01. Refer to "Scan Tool Testing/Scan Tool Connecting And Initial Checks", Testing and Inspection
Ignition must remain switched on for this.
When indicated on display:
Rapid data transfer HELP
select function XX
- Press buttons -0- and -8- to select "Read Measuring Value Block" and press -Q- button to confirm input.
When indicated on display:
Read Measuring Value Block Q
Input display group number XXX
- Press buttons -0-, -6- and -2- to select "display group number 062" and press -Q- button to confirm input.
Indicated on display:
Read Measuring Value Block 62 ->
1 2 3 4
- Check specified values for E-gas potentiometer voltages in display fields 1 and 2.
NOTE: Engine Control Module (ECM) calculates the voltage values of the angle sensors in percent relative to 5 volts and displays these percentage values. (5 volts supply voltage represents 100 %).
- Observe display field 1 and 2.
- Slowly depress accelerator pedal completely.
Percent indication in display field 1 must rise uniformly. The tolerance range of 3 to 93% will not be used completely during this.
Percent indication in display field 2 must decrease uniformly. The tolerance range of 97 to 3% will not be used completely during this.
NOTE:
- The reason why the value indicated in display field 1 climbs, while the value indicated in display field 2 decreases, has to do with the fact that the potentiometers (angle sensors) in the throttle valve control unit run in opposite directions.
- This means that the voltage tap of angle sensor 1 runs from 0 to 5 volts. (The more the throttle valve is opened, the larger the voltage; percent indication climbs).
- The voltage tap of angle sensor 2 runs from 5 to 0 volts. (The more the throttle valve is opened, the lower the voltage; the percentage decreases).
If indications do not resemble description:
- Check voltage supply and wire connections of throttle valve control module. Pay particular attention to harness connectors that could be loose or corroded.
- Check accelerator pedal position sensor. Testing and Inspection
Check voltage supply throttle valve control module
- Pull connector (2) off throttle valve control module.
- Switch ignition on.
- Connect multimeter to the following connector terminals for voltage measurement:
Harness connector Terminal Specified value
2+Ground (GND) about 5 V
2+6 about 5 V
If specified values are not obtained:
Check wire connections from Engine Control Module (ECM) to throttle valve control module.
Checking wire connections
- Pull connector (2) off throttle valve control module.
- Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Refer to "Scan Tool Testing/Wire And Component Test Using VAG1598/31 Test Box", Testing and Inspection
- Check the following wire connections for open circuit and short circuit to Ground (GND) and B+:
Harness connector Terminal VAG1598/31 test box Socket
1 92
2 83
3 117
4 84
5 118
6 91
- Repair open circuit or short circuit if necessary.
If no malfunctions are found in wires:
- Replace throttle valve control module.