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). 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).