TT Quattro Roadster V6-3.2L (BHE) (2005)
Electronic Throttle Control Module: Testing and Inspection
Throttle Valve Control Module, Checking
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
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Multimeter.
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Wiring diagram.
Test requirements
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The Motronic Engine Control Module (ECM) J220 fuses OK.
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Battery voltage at least 12.5 volts.
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All electrical consumers such as, lights and rear window defroster, switched off.
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Vehicles with automatic transmission, shift selector lever into position "P" or "N".
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A/C switched off.
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Ground (GND) connections between engine/transmission/chassis OK.
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Throttle valve must not be damaged or dirty.
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Coolant Temperature at least 80 degrees 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 :
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Throttle Drive (for Electronic Power Control (EPC)) G186
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Throttle Drive Angle Sensor 1 (for Electronic Power Control (EPC)) G187
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Throttle Drive Angle Sensor 2 (for Electronic Power Control (EPC)) G188
Test procedure
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Perform a preliminary check to verify the customers complaint. See: Powertrain Management/Computers and Control Systems/Testing and
Inspection/Scan Tool Testing and Procedures/General Diagnosis
Start diagnosis
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Connect the scan tool.
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Switch ignition on.
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Using the scan tool, check the throttle valve position (absolute) at idle stop:
Diagnostic text
Specified value
Throttle valve position (absolute)
Idle stop
3.0 to 25.0%
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Slowly depress the accelerator pedal to Wide Open Throttle (WOT) stop while observing the percentage display. The percentage display must
increase uniformly.
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Using the scan tool, check the throttle valve position (absolute) at Wide Open Throttle (WOT) stop:
Diagnostic text
Specified value
Throttle valve position (absolute)
Wide Open Throttle (WOT) stop
84.0 to 97.0%
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End diagnosis an switch ignition off.
If the specified values are not obtained: