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

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 and select vehicle system "01 - Engine electronics". Ignition must remain switched on for this. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/VAS 5051 Tester, Connecting and Selecting Functions" Testing and Inspection








Display on VAS5051:
- Select diagnostic function "08 - Read Measuring Value Block" in selection -1-.







Display on VAS5051:
1 - Enter display group Max. input value = 255
- Select function "062" in button field -2- for "display group number 062" and press Q button to confirm input.







Display on VAS5051:
- 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. In the process, the tolerance range of 3 to 93% is not completely utilized.
Percent indication in display field 2 must decrease uniformly. The tolerance range 97 to 3 % is not 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).
- Press "08 - erase DTC memory" to end function <- button.

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 for voltage measurement as follows:

Harness connector Specified value
Terminal

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 Engine Control Module (ECM), do not connect ECM. Refer to "Scan Tool Testing/Wire and Component Testing Using VAG1598/31 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.