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Home >> Volkswagen >> 1999 >> Jetta Sedan (9M2) L4-2.0L (AEG) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Relays and Modules - Computers and Control Systems >> Electronic Throttle Control Module >> Testing and Inspection >> Component Tests and General Diagnostics >> Throttle Valve Control Module J338, Checking >> With Manufacturer's Scan Tool

With Manufacturer's Scan Tool



Throttle valve control module, checking

Components of the throttle valve control module -J338-:
- Throttle drive (power accelerator actuation) -G186-
- Angle sensor -1- for for throttle drive (power accelerator actuation -G187-
- Throttle Position (TP) sensor -G69-
- Closed Throttle Position (CTP) switch -F60-

NOTE:
- Terminal pin assignment of the throttle valve control module differs on vehicles with or without a cruise control system (CCS). Identification: steering column switch with controls for CCS.
- If the throttle valve control module is replaced, the new control module must be matched to the Engine Control Module (ECM).
- On vehicles with an automatic transmission, the Transmission Control Module (TCM) must also be adapted.

Special tools and equipment
- V.A.G1551 Scan Tool (ST) or VAG1552 mobile scan tool with VAG1551/3 adapter cable
- VAG1598/22 test box
- Multimeter (Fluke 83 or equivalent)
- VW1594 adapter set
- Wiring diagram

Test conditions
- Throttle valve not damaged or dirty
- Accelerator pedal cable adjustment OK

NOTE: Only gold plated contacts can be used to repair the contacts in the connector for the throttle valve control module.

Checking Closed Throttle Position (CTP) switch -F60-
- Connect V.A.G1551 (VAG1552) Scan Tool (ST). [1][2]Reading and Clearing Diagnostic Trouble Codes
- Turn on ignition and press buttons -0- and -1- to insert "Engine Electronics" address word 01.

Indicated on display

Rapid data transfer HELP
Select function XX

- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08 and press -Q- button to confirm input.

Indicated on display

Read Measuring Value Block
Input display group number XXX

- Press buttons -0-, -5- and -4- to input display group number 54 (054) and press -Q- button to confirm input.

Indicated on display (1-4 = display fields)

Read Measuring Value Block 54 ->
1 2 3 4

- Check operating mode display in display field 2.

Display Group 54:






If the specified value is obtained:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.

Display constantly remains on one operating condition:






Continuation of check when display shows part throttle

- Disconnect 8-pin harness connector from throttle valve control module.






- Using auxiliary cables from VW1594, bridge the following harness connector terminals:
- Vehicles with CCS 1): terminals -2- + -6-
- Vehicles without CCS 1): terminals -3- + -7- and observe display

1) CCS = Cruise control system

If display jumps to idling:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.
- Replace throttle valve control module -J338-. Refer to item -14- in "Upper Section, Disassembling and Assembling" under "Engine/Intake Manifold". Intake Manifold
- Check DTC memory. If necessary, repair any malfunctions and erase DTC memory.
Reading Diagnostic Trouble Codes
Clearing Diagnostic Trouble Codes

- Adapt Engine Control Module (ECM) to throttle valve control module.
- Display readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from battery (B+) voltage, generate the readiness code again. Monitors, Trips, Drive Cycles and Readiness Codes

If display remains on idling:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.
- Check voltage supply of throttle valve control module and wiring to control module.

If the voltage supply and wiring is OK:
- Replace Engine Control Module (ECM).

Continuation of check when display constantly shows idling

- Disconnect 8-pin harness connector from throttle valve control module.

If display jumps to part throttle:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.
- Replace throttle valve control module -J338-. Refer to item -14- in "Upper Section, Disassembling and Assembling" under "Engine/Intake Manifold". Intake Manifold

- Check DTC memory. If necessary, repair any malfunctions and erase DTC memory.
Reading Diagnostic Trouble Codes
Clearing Diagnostic Trouble Codes

- Adapt Engine Control Module (ECM) to throttle valve control module.
- Display readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from battery (B+) voltage, generate the readiness code again. Monitors, Trips, Drive Cycles and Readiness Codes

If display remains on part throttle:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.
- Check voltage supply of throttle valve control module and wiring to control module.

If the voltage supply and wiring is OK:
- Replace Engine Control Module (ECM).

Checking throttle drive (power accelerator actuation) -G186- and angle sensor -1- for for throttle drive (power accelerator actuation) -G187-

Test requirements
- Min. coolant temp. 85 °C See display group 004, display field 3

Test sequence
- Connect V.A.G1551 (VAG1552) Scan Tool (ST).
Reading Diagnostic Trouble Codes
Clearing Diagnostic Trouble Codes

- With engine idling, switch ignition on and press buttons -0- and -1- to insert "Engine Electronics" address word 01.

Indicated on display

Rapid data transfer HELP
Select function XX

- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08 and press -Q- button to confirm input.

Indicated on display

Read Measuring Value Block
Input display group number XXX

- Press buttons -0-, -6- and -0- to input display group number 60 (060) and press -Q- button to confirm input.

Indicated on display: (1-4 = display fields)

Read Measuring Value Block 60 ->
1 2 3 4

- Check throttle valve angle at idling stop in display field 1.
- Check throttle valve position sensor at idling stop in display field 2.
- Check operating mode in display field 3.

Display Group 60:






If the specified values are obtained:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.

Continuation

If the specified values are not obtained:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.
- Disconnect 8 pin harness connector from throttle valve control module.






- Measure resistance of the throttle position sensor between the following Terminals:
- Vehicles with CCS 1) : terminals -7- + -8-
- Vehicles without CCS 1) : terminals -1- + -2-

1) CCS = Cruise control system

- Specified value: 3-200 ohms

If the specified value is not obtained:

- Replace throttle valve control module -J338-. Refer to item -14- in "Upper Section, Disassembling and Assembling" under "Engine/Intake Manifold". Intake Manifold
- Check DTC memory. If necessary, repair any malfunctions and erase DTC memory.
Reading Diagnostic Trouble Codes
Clearing Diagnostic Trouble Codes

- Adapt Engine Control Module (ECM) to throttle valve control module.

- Display readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from permanent battery (B+) voltage, generate the readiness code again. Monitors, Trips, Drive Cycles and Readiness Codes

If the specified value is obtained:
- Check voltage supply of throttle valve control module and wiring to control module.

If the voltage supply and wiring is OK:
- Replace Engine Control Module (ECM).

Checking Throttle Position (TP) sensor -G69-

Test sequence
- Connect V.A.G1551 (VAG1552) Scan Tool (ST). [1][2]Reading and Clearing Diagnostic Trouble Codes
- Switch ignition on and press buttons -0- and -1- to insert "Engine Electronics" address word 01.

Indicated on display

Read data transfer HELP
Select function XX

- Press buttons -0- and -8- to select "Read Measuring Value Block" function 08 and press -Q- button to confirm input.

Indicated on display

Read Measuring Value Block
Input display group number XXX

- Press buttons -0-, -5- and -4- to input display group number 54 (054) and press -Q- button to confirm input.

Indicated on display: (1-4 = display fields)

Read Measuring Value Block 54 ->
1 2 3 4

- Read throttle valve angle in display field 3.
Throttle valve in start position: 0-6 degree angle

- Slowly open throttle valve fully and observe angle display in display field 3. Figure must increase uniformly over complete range.

Display Group 54:






If the specified value is obtained:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.

NOTE: The displayed figure is dependent on the tolerances of the throttle valve potentiometer and does not correspond to the actual opening angle.

Continuation

If the figure does not increase uniformly:
- Replace throttle valve control module -J338-. Refer to item -14- in "Upper Section, Disassembling and Assembling" under "Engine/Intake Manifold". Intake Manifold

- Check DTC memory. If necessary, repair any malfunctions and erase DTC memory.
Reading Diagnostic Trouble Codes
Clearing Diagnostic Trouble Codes

- Adapt Engine Control Module (ECM) to throttle valve control module.

- Display readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from battery (B+) voltage, generate the readiness code again. Monitors, Trips, Drive Cycles and Readiness Codes

If the display constantly shows 0 degree angle or is above 90 degree angle






Continuation of check when display 0 degree angle

- Disconnect 8-pin harness connector from throttle valve control module.






- Bridge following harness connector terminals with auxiliary cables from VW1594 and observe display.
- Vehicles with CCS 1) : terminals 2 + 4
- Vehicles without CCS 1) : terminals 5 + 7

1) CCS = Cruise control system

If display jumps above 90 degree angle:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.
- Replace throttle valve control module -J338-. Refer to item -14- in "Upper Section, Disassembling and Assembling" under "Engine/Intake Manifold". Intake Manifold

- Check DTC memory. If necessary, repair any malfunctions and erase DTC memory.
Reading Diagnostic Trouble Codes
Clearing Diagnostic Trouble Codes

- Adapt Engine Control Module (ECM) to throttle valve control module.
- Display readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from permanent battery (B+) voltage, generate the readiness code again. Monitors, Trips, Drive Cycles and Readiness Codes

If display remains at 0 degree angle:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.
- Check voltage supply of throttle valve control module and wiring to control module.

If the voltage supply and wiring is OK:
- Replace Engine Control Module (ECM).

Continuation of check when display is above 90 degree angle

- Disconnect 8-pin harness connector from throttle valve control module.

If display jumps to 0 degree angle:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.
- Replace throttle valve control module -J338-. Refer to item -14- in "Upper Section, Disassembling and Assembling" under "Engine/Intake Manifold". Intake Manifold

- Check DTC memory. If necessary, repair any malfunctions and erase DTC memory.
Reading Diagnostic Trouble Codes
Clearing Diagnostic Trouble Codes

- Adapt Engine Control Module (ECM) to throttle valve control module.

- Display readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from permanent battery (B+) voltage, generate the readiness code again. Monitors, Trips, Drive Cycles and Readiness Codes

If display remains above 90 degree angle:
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Turn off ignition.
- Check voltage supply of throttle valve control module and wiring to control module.

If the voltage supply and wiring is OK:
- Replace Engine Control Module (ECM).

Checking voltage supply and wiring to control module
- Disconnect 8-pin harness connector from throttle valve control module.
- Connect multimeter to measure voltage at following harness connector terminals:
- Vehicles with CCS 1) : terminals -2- + -5-
- Vehicles without CCS 1) : terminals -4- + -7-

1) CCS = Cruise control system

- Turn on ignition.
Specified value: min. 4.5 V
- Turn off ignition.
- Connect multimeter to measure voltage at following harness connector terminals:
- Vehicles with CCS 1): terminals -2- + -6-
- Vehicles without CCS 1): terminals -3- + -7-

1) CCS = Cruise control system

- Turn on ignition.
Specified value: min. 9.0 V
- Turn off ignition.

If the specified values are not obtained:
- Remove wiper arms and plenum chamber cover.






- Connect VAG1598/22 test box to control module wiring harness.






- Check wiring between test box and harness connector for open circuit according to wiring diagram.

Vehicles with cruise control system:
- Terminal 1 + socket 74
- Terminal -2- + socket 67
- Terminal -4- + socket 75
- Terminal -5- + socket 62
- Terminal -6- + socket 69
- Terminal -7- + socket 59
- Terminal -8- + socket 66
- Wiring resistance: max. 1.5 ohms

Vehicles without cruise control system:
- Terminal -1- + socket 66
- Terminal -2- + socket 59
- Terminal -3- + socket 69
- Terminal -4- + socket 62
- Terminal -5- + socket 75
- Terminal -7- + socket 67
- Terminal -8- + socket 74
- Wiring resistance: max. 1.5 ohms

- Additionally check wires for short to one another.
Specified value: Infinity ohms

If no malfunction is found in the wiring:
- Check Engine Control Module (ECM) voltage supply. Refer to "Engine Control Module Voltage Supply" Testing and Inspection
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