With Manufacturer's Scan Tool
Throttle valve control module, checking
The engine identification ATQ indicates electronic gas activation.
This means that the throttle valve is activated by an electric motor in the throttle valve control module. This is activated by the Engine Control Module (ECM) based on the information from the Throttle Position (TP) sensor -G79- and sensor 2 for accelerator pedal position -G185-.
Components of throttle valve control module -J338-: Throttle valve drive -G186-, angle sensor 1 for throttle valve drive -G187-, and angle sensor 2 for throttle valve drive -G188-.
NOTE:
- If throttle valve control module is replaced, it must be adapted to the new control module to Engine Control Module (ECM).
- In vehicles with automatic transmissions the transmission control module must also be adapted.
Special tools and equipment
- V.A.G 1551 (or VAG 1552 mobile scan tool) with VAG 1551/3 cable
- VAG 1598/31 test box
- VAG 1526 multimeter or VAG 1715 multimeter
- VAG 1594 connector test kit
- Wiring diagram
Test condition
- Throttle valve must not be damaged or dirty.
- Coolant temperature must be at least 80°C, See Display group 04, display field 3
Test sequence
- Connect V.A.G 1551 scan tool (VAG 1552). Switch ignition on and select Engine Control Module (ECM) using address word 01. [1][2][3]Connecting VAG 1551 Scan Tool
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- to select "Read measuring value block" function 08. Press -Q- button to confirm input.
Indicated on display
Read Measuring Value Block HELP
Input display group number XXX
- Press buttons -0-, -6- and -2- to select "Display group number 62". Press -Q- button to confirm input.
Indicated on display (1 - 4 = display fields)
Read Measuring Value Block 62 ->
1 2 3 4
- Check throttle angle of sensor 1 -G187- at idle stop in display field 1
Specification: 3 - 93%
- Check throttle angle of sensor 2 -G188- at idle stop in display field 2
Specification: 97 - 3%
- Press accelerator pedal slowly until it reaches Wide Open Throttle (WOT) position, and observe angle display in display fields 1 and 2:
Percent indication in display field 1 must climb uniformly. In the process, the tolerance range of 3-93% is not completely utilized.
Percent indication in display field 2 must decrease uniformly. The tolerance range 97-3 % 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 module 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:
- Press -> button.
- Press buttons -0- and -6- to select "End data transfer" function 06. Press -Q- button to confirm input.
- Switch ignition off.
- Pull off 6-way connector (2) on the throttle valve control module.
- Measure resistance of throttle valve drive in throttle valve control module between terminals 3 + 5
Specification: 3 - 200 Ohms
If specified value is not obtained:
- Replace throttle valve control module (J338).
If the specified value is met:
- Check voltage supply of throttle valve control module and wires to control module.
- Test Throttle Position (TP) sensor and sensor 2 for accelerator pedal position.
If voltage supply and wires are in order:
- Replace Engine Control Module (ECM).
Checking Voltage Supply and Wires to Control Module
- Pull 6-way connector (2) off throttle valve control module.
- Connect multimeter to terminals 2 + 6 of connector to make voltage measurement.
- Turn ignition on.
Specification: at least 4.5 V
- Switch ignition off.
- Connect VAG 1598/31 test box to control module wiring harness. Engine Control Module (ECM) is not connected.
- Check wires between test box and connector for breaks (see wiring diagram):
Terminal 1 + socket 92
Terminal 2 + socket 83
Terminal 3 + socket 117
Terminal 4 + socket 84
Terminal 5 + socket 118
Terminal 6 + socket 91
Wire resistance: max. 1.5 Ohms
- Also check wires for shorts among one another.
- Also check wires for shorts to battery B+ or Ground (GND).
If no malfunctions are found in wires:
- Check voltage supply of Engine Control Module (ECM). Refer to Control Module Voltage Supply Check. Testing and Inspection