Audi Workshop Service and Repair Manuals

Components of throttle valve control part (J338):
Throttle valve drive (G186), angle sender 1 for throttle valve drive (G187) and angle sender 2 for throttle valve drive (G188).

Note:

If the throttle valve control part is replaced, the new control part must without fail be adapted to the engine control unit .

On vehicles fitted with an automatic gearbox the gearbox control unit must also be adapted:

=> Self-diagnosis for automatic gearbox 001; Repair group 01; Performing self-diagnosis

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ Test box V.A.G 1598/31
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Test conditions

• ● Throttle valve not damaged or dirty.

Test sequence

• ‒ → Connect test box V.A.G 1598/31 to control unit wiring harness. The engine control unit remains disconnected => Page 24-8.
• ‒ Measure resistance of throttle valve drive between contacts 117 + 118 on test box
      Specification: 3...200 ω

If the specification is not obtained:

• ‒ Replace throttle valve control part (J338).

If the specification is obtained:

• ‒ Check voltage supply of throttle valve control part and wiring to control unit => Page 24-50.

If the voltage supply and wiring is OK:

• ‒ Renew engine control unit => Page 24-126.

Checking voltage supply and wiring to control unit

• ‒ → Pull the 6-pin connector off the throttle valve control part.
• ‒ Connect the multimeter to measure voltage to contacts 2 + 6 of the connector.
• ‒ Switch on ignition.
      Specification: min. 4.5 V
• ‒ Switch off ignition.
• ‒ Connect the multimeter to measure voltage to contact 2 of the connector and earth.
• ‒ Switch on ignition.
      Specification: min. 4.5 V
• ‒ Switch off ignition.

If the specifications are not attained:

• ‒ → Connect test box V.A.G 1598/31 to control unit wiring harness. The engine control unit remains disconnected => Page 24-8.
• ‒ Check wiring for open circuit between test box and connector using current flow diagram:
      Contact 1+socket 92
      Contact 2+socket 83
      Contact 3+socket 117
      Contact 4+socket 84
      Contact 5+socket 118
      Contact 6+socket 91
      Wire resistance: max. 1.5 ω
• ‒ Additionally check wires for short to one another.
• ‒ Additionally check the wiring for short to battery positive or earth.

If no fault is detected in the wiring:

• ‒ Check engine control unit voltage supply => Page 24-121.