Angle Sensors For Throttle Drive -G187- and -G188-, Checking

Angle Sensors For Throttle Drive -G187- And -G188-, Checking







Special tools and workshop equipment required

- V.A.G 1526 A Multimeter.
- V.A.G 1594 A Connector test kit.
- V.A.G 1598/31 Test box.
- VAS 5051.
- VAS 5051/1 adapter.

Angle sensor 1 for throttle drive (power accelerator activation) -G187- and angle sensor 1 for throttle drive (power accelerator activation) -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 vehicle diagnostic, testing and information system VAS 5051 and select vehicle system "01 - Engine electronics" in selection. Ignition must be switched on. Connecting VAS 5051 Scan Tool

Display on VAS 5051:







- Under -1- select diagnostic function "08 - Read measured value block".

Display on VAS 5051:







1 - Enter display group.
- Enter "062" for "display group number 062" in field -2- and confirm entry by pressing -Q- button.

Display on VAS 5051:







- Check specifications for electronic throttle potentiometer voltages in display fields -1- and -2-.

Display Group 062:

- Observe readouts in display fields 1 and 2.
- Slowly depress accelerator pedal.

Percentage displayed in field 1 should rise evenly. Tolerance range from 3..0.93 % is not fully utilized.
Percentage displayed in field 2 should fall evenly. Tolerance range from 97..0.3 % is not fully utilized.

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 Module -J338- run in opposite directions.
- This means that the voltage 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 of angle sensor 2 runs from 5 to 0 volts. (The more the throttle valve is opened, the lower the voltage; the percentage decreases).

- Exit function "08 - Read measured value block" by pressing <- button.

If the displays are not as described:
- Check Throttle Valve Control Module -J338-voltage supply and wiring. Pay particular attention to connectors, which may be disconnected or corroded. Throttle Valve Control Module -J338-, Checking
- Check Throttle Position (TP) sensor 2 -G185-. TP Sensor 1 -G79- and Throttle Position Sensor 2 -G185-

Checking Voltage Supply To Throttle Valve Control Module -J338-.

- Disconnect connector from Throttle Valve Control Module -J338-.
- Switch ignition on.







- Connect multimeter as follows to measure voltage:

Connector Specified value
terminal

2 + ground (GND) approx. 5 V
2 + 6 approx. 5 V

If the specified values are not obtained:

Checking wire connections







- Disconnect connector from Throttle Valve Control Module -J338-.
- Connect test box V.A.G 1598/31 to wiring harness for Engine Control Module (ECM); do not connect Engine Control Module (ECM). Wiring and Component Testing Using VAG1598/31 Test Box
- Check for open circuit, short to ground (GND), or short to positive (B+) in following wiring connections:

Connector Test box VAG 1598/31
terminal Socket

1 92
2 83
3 117
4 84
5 118
6 91

- Repair any open/short circuit as necessary.

If no malfunctions are found in wires:
- Replace Throttle Valve Control Module -J338-.