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/Connecting VAG 1551/VAS 5051 Scan Tool" 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.

Display group 062:

- 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:







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/Scan Tool Connecting and Initial Checks/Connecting VAG 1598/31 Test Box" Testing and Inspection
- Check the following wire connections for open circuit and short circuit to Ground (GND) and B+:







- Repair open circuit or short circuit if necessary.

If no malfunctions are found in wires:
- Replace throttle valve control module.