With Generic Scan Tool
Throttle Valve Control Module, Checking
NOTE: Use only gold-plated terminals when servicing terminals in harness connector of throttle valve control module.
Vehicles with engine code AEG (80-pin Engine Control Module -ECM-)
Function
Components of throttle valve control module -J338-:
- Closed Throttle Position (CTP) Switch -F60-
- Throttle Position (TP) sensor -G69-
- Throttle Position (TP) sensor -G88-
- Throttle Position (TP) Actuator -V60-
If the complete throttle valve control module is current-less (e.g. connector disconnected) the throttle valve moves into a particular, specified mechanical position, which signals an increased idle speed with an engine at operating temperature.
If only the Throttle Position (TP) Actuator -V60- is current-less, the throlle valve also moves into the specified mechanical position (emergency running gap), however, since Closed Throttle Position (CTP) Switch -F60- can still be recognized, an "almost normal" is reached via the respective ignition angle retardation.
If the Engine Control Module (ECM) detects a malfunction at Throttle Position (TP) Sensor -G69-, Throttle Position (TP) Actuator -V60- is switched current-less by the Engine Control Module (ECM) and the throttle valve moves into the specified mechanical position (Emergency running gap) again.
Note: Terminal assignment at throttle control unit is different in vehicles with and without cruise control. Characteristic: Steering column switch with operating unit for cruise control.
Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 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 like, for example, lights and rear window heating must be switched off.
- Parking brake must be engaged or else daylight 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.
- Throttle valve must be in Closed Throttle Position (CTP)
- Coolant temperature must be at least 80°C, Diagnostic mode 1: Check measuring values; PID 5, Coolant temperature. Diagnostic Mode 1: Check Measured Values
Test sequence
- Disconnect the 8-pin connector at the throttle valve control module.
Check resistance
- Measure resistance of Throttle Position (TP) Actuator -V60- between the following terminals.
Vehicles with cruise control: Terminal 7 + 8
Specified value: 3...200 ohms
Vehicles without cruise control: Terminal 1 + 2
Specified value: 3...200 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.
- 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.
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 the following connector terminals for voltage measurement.
Vehicles with cruise control: Terminal 2 + 5
Vehicles without cruise control: Terminal 4 + 7
- Switch ignition on. Specified value: at least 4.5 V
- Switch ignition off.
- Connect multimeter to the following connector terminals for voltage measurement:
Vehicles with cruise control: Terminal 2 + 6
Vehicles without cruise control: Terminal 3 + 7
- Switch ignition on. Specified value: at least 9.0 V
- Switch ignition off.
- Connect test box to control module wiring harness.
- Check wires between test box and 8-pin connector for open circuit according to wiring diagram.
- Vehicles with cruise control:
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
Wire resistance: max: 1.5 ohms
- Vehicles without cruise control:
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
Wire resistance: max: 1.5 ohms
- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+. Specified value: infinite ohms
If no malfunctions are found in wires:
- Check voltage supply of Engine Control Module (ECM)
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code Monitors, Trips, Drive Cycles and Readiness Codes