Electronic Throttle Actuator Position Sensor: Testing and Inspection
Angle Sensor -1- For Throttle Drive (Power Accelerator Actuation) -G187 And Angle Sensor -2- For Throttle Drive (Power Accelerator Actuation) - G188, Checking
The angle sensor -1- for throttle drive (power accelerator actuation) -G187 and angle sensor -2- for throttle drive (power accelerator actuation) - G188 inform the engine control module of the position of the throttle valve. Both angle sensors are located in the throttle valve control module.
- Connect vehicle diagnostic, testing and information system VAS5051 or VAG1551 scan tool and select engine electronics control module by entering address word "01". When doing this the ignition must be switched on. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAS 5051/ VAG 1551 Scan Tool" Testing and Inspection
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- to select function "Read Measuring Value Block" and confirm entry with -Q- button.
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 confirm entry with -Q- button.
Indicated on display
Read Measuring Value Block 62 ->
1 2 3 4
- Check specified display values for electronic throttle potentiometer voltages.
Display Group 062:
- Observe display fields 1 and 2.
- Slowly depress accelerator pedal to full throttle position.
The percentage value in display field 1 should rise steadily, but without covering the full tolerance range between 3 - 93 %.
The percentage value in display field 2 should also rise steadily but without covering the full range of values (in this case 4 - 49 %).
If the display values do not appear as described:
- Check voltage supply and wiring to accelerator position senders.
Observe harness connectors for the following:
Loose connectors, not properly engaged or corroded.
- Check accelerator position sensors. Testing and Inspection
NOTE:
- The reason why the value in display field I rises and the value in display field 2 falls is because the potentiometers (angle senders) in the throttle valve control module work in opposite directions.
- The percentage value for the first potentiometer increases as the voltage rises towards 5V because the voltage at this potentiometer increases as the throttle valve opens.
- The percentage value for the second potentiometer decreases as the voltage drops away from 5V and towards 0V because the voltage at this potentiometer decreases as the throttle valve opens.
Checking voltage supply to throttle valve control module
- Disconnect harness connector from throttle valve control module.
- Switch ignition on.
- Connect hand-held multimeter (voltage range) between the following sockets on connector:
6-pin connector on Specification
wiring harness, socket
2 + Ground (GND) approx. 5 V
2+6 approx. 5V
If the specifications are not obtained, test wiring connections from engine control module to throttle valve control module.
If the readouts match the specifications, test also the signal wires and activation wires for the throttle valve positioner.
Checking wiring for voltage, signal and activation
- Connect VAG1598/31 test box to wiring harness for engine control module. Do not connect to the engine control module itself. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG1598/31 Test Box" Testing and Inspection
Test the following wiring connections for open circuits and short to B+ or Ground (GND).
6-pin connector on VAG1598/31 test box,
wiring harness, socket
socket
1 92
2 83
3 117
4 84
5 118
6 91
Resistance in wiring: max. 1.5 Ohms
- Repair any open/short circuit as necessary.
If no wiring malfunction is detected:
- Replace throttle valve control module.