With Manufacturer's Scan Tool
Throttle Valve Control Module, Checking
Components of throttle valve control module -J338-: Throttle valve drive -G186-, angle sender 1 for throttle valve drive -G187- and angle sender 2 for throttle valve drive -G188-.
NOTE:
- If the throttle valve control module is replaced, the new control module must without fail be adapted to the Engine Control Module (ECM).
- On vehicles fitted with an automatic gearbox the gearbox control module must also be adapted:
Special tools, test equipment and auxiliary items
- Scan tool V.A.G 1551 or vehicle system tester V.A.G 1552 with cable VAG 1551/3B
- Test box VAG 1598/31
- Multimeter (Fluke 83 or equivalent)
- Adapter set V.A.G 1594
- Wiring diagram
Test conditions
- Throttle valve not damaged or dirty
- On vehicles with automatic gearbox selector lever in "P" or "N" position
- Coolant temperature must be at least 85 °C, see display group 04, display zone 3
NOTE: Only gold-plated contacts can be used to repair the contacts in the connector for the throttle valve control module.
- Connect the scan tool V.A.G 1551 (V.A.G 1552) Then switch ignition on and select engine control module with the "Address word" 01.
Indicated on display
Rapid data transfer HELP
Select function XX
- Press keys 0 and 8 for the function "Read measuring value block" and confirm entry with Q key.
Indicated on display
Read measuring value block
Input display group number XXX
- Press keys 0, 6 and 2 for the "Display group number 62" and confirm entry with Q key.
- Check throttle valve angle of sender 1 -G187- on idle speed stop in display zone 1.
- Check throttle valve angle of sender 2 -G188- on idle speed stop in display zone 2.
Display Group 62:
- Depress accelerator slowly until full throttle position and observe angles displayed in display zones 1 and 2:
The percent display in display zone 1 must rise continuously and evenly. The full tolerance range 3-93% is not always displayed.
The percent display in display zone 2 must fall continuously and evenly. The full tolerance range 97-3% 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 angle senders in the throttle valve control modules run in counter directions.
- The voltage of angle sender 1 moves toward 5 volts. (The more the throttle valve is opened the higher the voltage; percentage increases).
- The voltage of angle sender 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 -> key.
- Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
- Switch off ignition.
Continuation
- Press -> key.
- Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
- Switch off ignition.
- Pull 6-pin connector off throttle valve control module -arrow-.
- Measure resistance from throttle valve drive between contacts 3 and 5
Specification: 1.0-5.0 Ohms
If the specification is not obtained:
- Replace throttle valve control module -J338-, item 20.
- Check DTC memory, if necessary, repair any malfunctions and then erase DTC memory
- Adapt engine control module to throttle valve control module.
- Read-out the readiness code. If the DTC memory has been erased or the engine control module was disconnected from permanent positive, the readiness code must be generated again.
If the specification is obtained:
- Check voltage supply of throttle valve control module and wiring to control module.
- Check accelerator pedal sender (EPC).
If the voltage supply and wiring is OK:
- Replace Engine Control Module (ECM).
Checking voltage supply and wiring to control module
- Pull 6-pin connector off throttle valve control module -arrow-.
- Connect multimeter to measure voltage at contacts 2 and 6.
- Switch on ignition.
Specification: min. 4.5 V
- Switch off ignition.
- Connect multimeter to measure voltage at connector contact 2 and Ground.
- Switch on ignition.
Specification: min. 4.5 V
- Switch off ignition.
If the specifications are not attained:
- Remove inner plenum chamber cover, left:
- Connect test box V.A.G 1598/31 to control module wiring harness. The engine control module is not connected by this action.
- Check wiring for open circuit between test box and connector contacts:
- Contact 1 + Socket 92
- Contact 2 + Socket 83
- Contact 3 + Socket 117
- Contact 4 + Socket 84
- Contact 5 + Socket 118
- Contact 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.
Specification: Infinity Ohms
If no wiring problem is detected:
- Check Engine Control Module (ECM) voltage supply.