Throttle Valve Control Module J338 , Checking Audi TT 8N

Note. Use only gold-plated terminals when servicing terminals in harness connector of Throttle Valve Control Module J338.

Special tools, testers and auxiliary items required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Motronic Engine Control Module (ECM) J220 fuses OK.
2. Battery voltage at least 12.5 volts.
3. All electrical consumers such as, lights and rear window defroster, switched off.
4. Vehicles with automatic transmission, shift selector lever into position "P" or "N".

1. A/C switched off.
2. Ground (GND) connections between engine/transmission/chassis OK.
3. Throttle valve must not be damaged or dirty.
4. Coolant Temperature at least 80°C.

Function

Throttle valve operation occurs by an electric motor (Throttle Drive (for Electronic Power Control (EPC)) G186) in Throttle Valve Control Module J338. It is operated by Motronic Engine Control Module (ECM) J220 according to specifications of Throttle Drive Angle Sensor 1 (for Electronic Power Control (EPC)) G187/Throttle Drive Angle Sensor 2 (for Electronic Power Control (EPC)) G188.

Components of Throttle Valve Control Module J338

1. Throttle Drive (for Electronic Power Control (EPC)) G186
2. Throttle Drive Angle Sensor 1 (for Electronic Power Control (EPC)) G187
3. Throttle Drive Angle Sensor 2 (for Electronic Power Control (EPC)) G188

Test procedure

1. Perform a preliminary check to verify the customers complaint. Refer to --> «General Diagnosis»(ref-276276-S40851803372008010300000)

Start diagnosis

1. Connect the scan tool.
2. Switch ignition on.
3. Using the scan tool, check the throttle valve position (absolute) at idle stop

1. Slowly depress the accelerator pedal to Wide Open Throttle (WOT) stop while observing the percentage display. The percentage display must increase uniformly.
2. Using the scan tool, check the throttle valve position (absolute) at Wide Open Throttle (WOT) stop

1. End diagnosis and switch ignition off.

If the specified values are not obtained

1. Remove the air hose - arrows -.

Scheme 30

1. Disconnect the Throttle Valve Control Module J338 electrical harness connector - 3 -.

Checking internal resistance

1. Using a multimeter , check the Throttle Drive (for Electronic Power Control (EPC)) G186 at the Throttle Valve Control Module J338 terminals 3 to 5 for resistance.

Specified value: 1.0 to 5.0 ohms (at 20°C)

If the specification was not obtained

1. Replace the Throttle Valve Control Module J338. Refer to --> «24 MULTIPORT FUEL INJECTION (MFI)»(ref-276275-S13244009452008010300000) .

If the specification was obtained

1. Check the voltage supply of the Throttle Valve Control Module J338 to the Motronic Engine Control Module (ECM) J220 «Checking voltage supply and wiring»(ref-276276-S08713112582008022500000) .