With Manufacturer's Scan Tool
Throttle Valve Control Module -J338-, Checking
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:
- If the Throttle Valve Control Module -J338- is replaced, the new control module must be adapted to the Motronic Engine Control Module (ECM) -J220-.
- On vehicles with an automatic transmission, the transmission control module must also be adapted.
Special tools, test equipment and auxiliary items
- VAG 1551 scan tool or VAG 1552 mobile scan tool with VAG 1551/3B cable
- VAG 1598/31 test box
- VAG 1526 hand multimeter or VAG 1715 multimeter
- VAG 1594 adapter set
- Electrical Wiring Diagram
Test conditions
- Engine not running, ignition switch on
- Throttle valve not damaged or dirty
- On vehicles with automatic transmission selector lever in "P" or "N" position
- Engine Coolant Temperature (ECT) must be at least 80 °C, see display group 04, display zone 3
NOTE: Only gold-plated terminals can be used to repair the terminals in the connector for the Throttle Valve Control Module -J338-.
- Connect VAG 1551 scan tool (or VAG 1552). Switch ignition on and select Motronic Engine Control Module (ECM) -J220- with "Address word" 01. Connecting scan tool and selecting Motronic Engine Control Module (ECM) -J220-. [1][2][3]Connecting VAG 1551 Scan Tool
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- for function "Read measuring value block" and confirm entry with -Q- button.
Indicated on display
Read measuring value block
Input display group number XXX
- Press buttons -0-, -6- and -2- for "Display group number 62" and confirm entry with -Q- button.
Indicated on display (1 to 4 = Display zones)
Read measuring value block 62 ->
1 2 3 4
- Check throttle valve angle at idling stop from Throttle valve angle sensor 1 -G187- in display zone 1:
Specification: 10 to 88 %
- Check throttle valve at idling stop from Throttle valve angle sensor 2 -G188- in display zone 2:
Specification: 89 to 11 %
- Depress accelerator slowly until full throttle position and observe angles displayed in display zones 1 and 2:
- Percent figure in display zone 1 must rise continuously and evenly. Full tolerance range 10 to 88 % is not always displayed.
- Percent figure in display zone 2 must fall continuously and evenly. Full tolerance range 89 to 11 % is not always displayed.
NOTE:
- The reason why the display in display zone 1 rises and the display in display zone 2 falls is because the potentiometers (angle sensors) in the angle sensors run in opposite directions.
- The voltage of angle sensor 1 moves toward 5 volts. (The more the throttle valve is opened the higher the voltage; percentage increases).
- While the voltage of angle sensor 2 drops from 5 volts toward 0 volt. (The more the throttle valve is opened the lower the voltage; percentage falls).
If the specifications are obtained:
- Press -> button.
- Press buttons -0- and -6- for function "End output" and confirm entry with -Q- button.
- Switch off ignition.
Continuation
If the displays do not indicate as described:
- Press -> button.
- Press buttons -0- and -6- for function "End output" and confirm entry with -Q- button.
- Switch off ignition.
- Disconnect 6-pin connector from Throttle Valve Control Module -J338- -arrow-.
- Measure resistance from throttle valve drive between terminals 3 and 5
Specification: 1.0 to 5.0 Ohms
If the specification is not obtained:
- Replace Throttle Valve Control Module -J338-, item 22.
- Check DTC Memory, if necessary, repair any malfunctions and then Erase DTC Memory. Reading Diagnostic Trouble Codes
- Adapt Motronic Engine Control Module (ECM) -J220- to Throttle Valve Control Module -J338-.
- Read readiness code. If DTC memory has been erased or Motronic Engine Control Module (ECM) -J220- was disconnected from battery positive, readiness code must be generated again.
Monitors, Trips, Drive Cycles and Readiness Codes
Monitors, Trips, Drive Cycles and Readiness Codes
If the specification is obtained:
- Check voltage supply of Throttle Valve Control Module -J338- and wiring to control module.
- Check Throttle Position (TP) sensors (E-Gas).
If the voltage supply and wiring is OK:
- Replace Motronic Engine Control Module (ECM) -J220-.
Checking voltage supply and wiring to control module
- Disconnect 6-pin connector from Throttle Valve Control Module -J338- -arrow-.
- Connect multimeter to measure voltage to terminals 2 + 6 of connector.
- Switch on ignition.
Specification: min. 4.5 V
- Switch off ignition.
- Connect multimeter to measure voltage at connector terminal 2 and Ground (GND).
- Switch on ignition.
Specification: min. 4.5 V
- Switch off ignition.
If the specifications are not obtained:
- Remove inner plenum chamber cover, left.
- Connect VAG 1598/31 test box to control module wiring harness. Motronic Engine Control Module (ECM) -J220- is not connected by this action.
- Check wiring between test box and connector terminals for open circuit using Electrical 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
- Additionally check wires for short to one another.
Specification: Infinity Ohms
- Check wiring additionally for short circuit to battery positive or Ground (GND).
Specification: Infinity Ohms
If no wiring malfunction is found:
- Check Motronic Engine Control Module (ECM) -J220- voltage supply. Engine Control Module (ECM) Voltage Supply, Checking