Throttle Valve Control Module, Checking: Notes
Use only gold-plated terminals when servicing terminals in harness connector of Mass Air Flow (MAF) Sensor -J338-.
Special tools and workshop equipment required
- Multimeter.
- Wiring diagram.
Test requirements
- The Motronic Engine Control Module (ECM) - J220- fuses OK.
- Battery voltage at least 12.5 volts.
- All electrical consumers such as, lights and rear window defroster, switched off.
- Vehicles with automatic transmission, shift selector lever into position "P" or "N".
- A/C switched off.
- Ground (GND) connections between engine/transmission/chassis OK.
- Throttle valve must not be damaged or dirty.
- Coolant Temperature at least 80° C.
Function
Throttle valve operation occurs via an electric motor (Throttle Drive (for Electronic Power Control (EPC)) -G186-) in Throttle Valve Control Module - J338-. It is operated by Motronic Engine Control Module (ECM) -J220- according to specifications of Throttle Position (TP) Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185 -.
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-
Test procedure
-- Perform a preliminary check to verify the customers complaint. Refer to GENERAL DIAGNOSIS .
Start diagnosis
-- Connect the scan tool.
-- Switch ignition on.
-- Using the scan tool, check the throttle valve position (absolute) at idle stop:
| Diagnostic text | Specified value | |||
|---|---|---|---|---|
| Throttle valve position (absolute) | ||||
|
3.0 to 25.0% | |||
-- Slowly depress the accelerator pedal to Wide Open Throttle (WOT) stop while observing the percentage display. The percentage display must increase uniformly.
-- Using the scan tool, check the throttle valve position (absolute) at Wide Open Throttle (WOT) stop:
| Diagnostic text | Specified value | |||
|---|---|---|---|---|
| Throttle valve position (absolute) | ||||
|
84.0 to 97.0% | |||
-- End diagnosis and switch ignition off.
If the specified values are not obtained:
-- Remove the Throttle Valve Control Module -J338 - far enough so that the electrical connector terminals are reached.
-- Disconnect the Throttle Valve Control Module -J338- electrical harness connector -arrow-.
Checking resistance
-- Using a multimeter, check the Throttle Drive (for Electronic Power Control (EPC)) -G186- at the Throttle Valve Control Module -J338- terminals 3 to 5 for resistance.
Specified value: 1.0 to 5.0 Ω (at 20° C)
If the specification was not obtained:
-- Replace the Throttle Valve Control Module - J338-.
If the specification was obtained:
-- Check the voltage supply of the Throttle Valve Control Module -J338- to the Motronic Engine Control Module (ECM) -J220- THROTTLE VALVE CONTROL MODULE, CHECKING .
--.