Throttle Valve Control Module, Checking

Throttle Valve Control Module, Checking

NOTE: Use only gold-plated terminals when servicing terminals in harness connector of throttle valve control module.

Function
The throttle valve activation occurs via an electric motor (throttle drive) in the throttle valve control module. It is activated by the Engine Control Module (ECM) according to specifications of the two sensors, Throttle Position (TP) Sensor -G79- and accelerator pedal position sensor 2 -G185-. function of the EPC system.

Components of throttle valve control module -J338-:
- Throttle Drive (for Electronic Power Control (EPC)) -G186-
- Throttle Drive Angle Sensor 1 (for Electronic Power Control (EPC)) -G187-
- Throttle Drive Angle Sensor 2 (for Electronic Power Control (EPC)) -G188-

Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram

Test requirements







- The respective fuses of Motronic Engine Control Module (ECM) -J220- must be OK.
- Battery voltage must be at least 11.5 volts.
- All electrical consumers such as: lights and rear window defroster must be switched off.
- Parking brake must be engaged or else day time driving lights will be switched on.
- If vehicle is equipped with an A/C system, it must be switched off.
- Ground (GND) connections between engine and chassis must be OK.
- Throttle valve must not be damaged or dirty.
- Coolant temperature must be at least 80 degrees C. Diagnostic mode 1: Check measured values; PID 5, Coolant temperature. Diagnostic Mode 1: Check Measured Values

Function test
- Connect diagnostic tester. Diagnostic Tester, Connecting
- Switch ignition on.
- Under address word 33, select "Diagnostic mode 1: Check measured values."
- Select the measuring value "PID 17: Throttle valve position (absolute)."
- Check specified value of throttle valve position (absolute) at idle stop:







- Slowly depress accelerator pedal to Wide Open Throttle (WOT) stop while observing the percentage display.

The percentage display must increase uniformly.
- Check specified value of throttle valve position (absolute) at Wide Open Throttle (WOT) stop:







- End diagnosis and switch ignition off.

If specified values are not obtained:







- Disconnect the 6-pin connector (arrow) from Throttle Valve Control Module -J338-

Checking resistance







- Check resistance of Throttle Drive (for Electronic Power Control (EPC)) -G186- in Throttle Valve Control Module -J338- between terminals 3 + 5

Specified value: 1.0 to 5.0 Ohms

If specified value is not obtained:
- Replace Throttle Valve Control Module -J338-.
- Erase DTC memory of Engine Control Module (ECM). Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If specified value is obtained:
- Check voltage supply of throttle valve control module and wiring to control module.
- Check Throttle Position (TP) Sensor -G79- and Accelerator pedal position sensor 2 -G185-.

If voltage supply and wires are OK:
- Replace Motronic Engine Control Module (ECM) -J220-.

Checking voltage supply and wiring to control module







- Connect multimeter to connector terminals 2 + 6 for voltage measurement.
- Switch ignition on.

Specified value: at least 4.5 V

- Switch ignition off.

If there is no voltage:
- Check wires to control module according to wiring diagram.

Check wires to control module
- Connect test box to control module wiring harness. connect test box for wiring test. Test Box, Connecting For Wiring Test







- Check wires between test box and 6-pin connector to Engine Control Module (ECM) for open circuit according to 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

- Check wires for short circuit to each other, to vehicle Ground (GND) and to B+.

Specified value: Infinite Ohms

- Erase DTC memory of Engine Control Module (ECM). Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If no malfunctions are found in wires:
- Check voltage supply of Engine Control Module (ECM) according to wiring diagram.
- Erase DTC memory of Engine Control Module (ECM). Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes