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-
- Angle sensor -2- for for throttle drive (power accelerator actuation) -G188-
NOTE:
- If the throttle valve control module is replaced, the new control module must be matched to the Engine Control Module (ECM). Refer to "Engine Control Module (ECM) to Throttle Valve Control Module, Adaptation", Testing and Inspection
- On vehicles with an automatic transmission, the Transmission Control Module (TCM) must also be adapted.
Special tools and equipment
- VAG1551 Scan Tool (ST) or VAG1552 mobile scan tool with VAG1551/3 adapter cable
- VAG 1598/31 test box
- Multimeter (Fluke 83 or equivalent)
- VW1594 adapter set
- Wiring diagram
Test conditions
- Throttle valve not damaged or dirty.
- Automatic transmission selector lever in "P" or "N" position (if equipped)
- Coolant temperature at least 85 °C. See display group 04, display field 3
NOTE: Only gold plated contacts can be used to repair the contacts in the connector for the throttle valve control module.
- Connect VAG1551 (VAG1552) Scan Tool (ST).
- 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 -0-1-6- and -2- to input display group number 62 (062) and press -Q- button to confirm input.
- Check angle sensor -1- for for throttle drive (power accelerator actuation) -G187- on idle speed stop in display field 1.
- Check angle sensor -2- for for throttle drive (power accelerator actuation) -G188- on idle speed stop in display field 2.
Display Group 062:
- Depress accelerator slowly until Wide Open Throttle (WOT) position and observe angles displayed in display fields 1 and 2.
The percentage displayed in display field 1 must rise continuously and evenly. The full tolerance range (3-93%) is not always displayed.
The percentage displayed in display field 2 must fall continuously and evenly. The full tolerance range (97-3%) is not always displayed.
NOTE:
- The display in display field 1 rises and the display in display field 2 falls because the potentiometers (angle sensors) in the throttle valve control modules run in opposite directions.
- This means that the voltage of one angle sensor 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 volts (the more the throttle valve is opened the lower the voltage; percentage falls).
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.
- Switch ignition off.
Continuation
- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Switch ignition off.
- Disconnect 6-pin harness connector from throttle valve control module (arrow).
- Measure resistance from throttle valve drive between terminals -3- and -5-
Specified value: 1.0-5.0 ohms
If the specified value is not obtained:
- Replace throttle valve control module - J338- , item 10. Refer to "Intake Manifold Upper Section, Disassembling and Assembling" under "Fuel Delivery and Air Induction/Variable Induction System",
- Check DTC memory. If necessary, repair any malfunctions and erase DTC memory.
- Adapt Engine Control Module (ECM) to throttle valve control module.
- Display readiness code.
If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from permanent battery (B+) voltage, the readiness code must be generated again.
If the specified value is obtained:
- Check voltage supply of throttle valve control module and wiring to control module.
- Check accelerator pedal sensor.
If the voltage supply and wiring is OK:
- Replace Engine Control Module (ECM).
Checking voltage supply and wiring to control module
- Disconnect 6-pin harness connector from throttle valve control module (arrow).
- Connect multimeter to measure voltage at terminals -2- and -6-.
- Switch ignition on.
Specified value: min. 4.5 V
- Switch ignition off.
- Connect multimeter to measure voltage at harness connector terminal -2- and Ground.
- Switch ignition on.
Specified value: min. 4.5 V
- Switch ignition off.
If the specified values are not attained:
- Remove wiper arms and plenum chamber cover.
- Connect VAG1598/31 test box to Engine Control Module (ECM) wiring harness. Engine Control Module (ECM) is not connected by this action.
- Check wiring for open circuit between test box and harness connector terminals:
- Terminal 1 + socket 92
- Terminal -2- + socket 83
- Terminal -3- + socket 117
- Terminal -4- + socket 84
- Terminal -5- + socket 118
- Terminal -6- + socket 91
- Wiring resistance: max. 1.5 ohms
- Additionally, check wires for short to one another.
Specified value: infinity ohms
- Check wiring additionally for short circuit to battery positive or Ground.
Specified value: infinity ohms
If no malfunction is found in the wiring:
- Check Engine Control Module (ECM) voltage supply. Refer to "Engine Control Module (ECM) Voltage Supply, Checking", Testing and Inspection