With Manufacturer's Scan Tool

Throttle valve control module

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: When the throttle valve control module is replaced, it is absolutely necessary to adapt the new control module to the Engine Control Module (ECM).


Special tools and equipment
- V.A.G 1551 scan tool (or VAG 1552 mobile scan tool) with VAG 1551/3B cable
- VAG 1598/31 adapter cable
- VAG 1526 multimeter or VAG 1715 multimeter
- VAG 1594 connector test kit
- Wiring diagram

Test requirements
- Throttle valve must not be damaged or dirty.
- Coolant temperature must be at least 80 °C, See display group 04, display field 3
- Ignition switched on, engine not running

Test sequence
- Connect V.A.G 1551 scan tool (VAG 1552). Then switch ignition on and select the Engine Control Module (ECM) using address word 01. (connecting scan tool and selecting ECM). [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
Enter display group number XXX


- Press buttons 6-, -0- and -2- to select "Display group number 62". Press -Q- button to confirm input.

Indicated on display: (1 to 4 = display fields)


Read measuring value block 62 ->
1 2 3 4


- Check throttle angle of angle sensor -1- for throttle drive (power accelerator actuation) -G187- at idle stop in display field 1. Specification: 3 to 93 %
- Check throttle angle of angle sensor -2- for throttle drive (power accelerator actuation) -G188- at idle stop in display field 2. Specification: 97 to 3 %
- Press gas 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 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 value indicated in display field 1 increases, but the value indicated in display field 2 decreases, because 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.







- Connect VAG 1598/31 adapter cable to control module wiring harness. Engine Control Module (ECM) is not connected.
- Measure resistance of throttle valve drive between test box sockets 117 + 118. Specification: 1 to 5 Ohms

If specified value is not obtained:
- Replace throttle valve control module -J338-.

If specified value is obtained:
- Check voltage supply of throttle valve control module and wiring to control module.
- Check Throttle Position (TP) sensor and sensor 2 for accelerator pedal position.

If voltage supply and wires are OK:
- Replace Engine Control Module (ECM).

Checking voltage supply and wiring to control module







- Disconnect 6-pin connector -2- at the throttle valve control module.







- Connect multimeter to terminals 2 + 6 of connector to make voltage measurement.
- Switch ignition on. Specification: at least 4.5 V
- Switch ignition off.







- Connect multimeter to terminal 2 of connector and Ground (GND) for voltage measurement.
- Switch ignition on. Specification: at least 4.5 V
- Switch ignition off.

If specified values are not obtained:







- Connect VAG 1598/31 adapter cable to control module wiring harness. Engine Control Module (ECM) is not connected.







- Check for open circuits in wires between test box and connector according to 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 short circuit to each other.
- Also check wires for short circuits to B+ or Ground (GND).

If no malfunctions are found in wires:
- Check voltage supply of Engine Control Module (ECM).