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 Engine Control Module (ECM) -J623- 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 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 by an electric motor (Throttle Drive (for Electronic Power Control (EPC)) -G186-) in the Throttle Valve Control Module - J338-. It is operated by the Engine Control Module (ECM) -J623- and the Accelerator Pedal Position Sensor -G79- /Accelerator Pedal Position Sensor 2 -G185-.
The Throttle Valve Control Module -J338- is made up of the following components:
- 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-
The Throttle Valve Control Module -J338- cannot be serviced separately and must be serviced as a unit.
Test procedure
Always set the parking brake first. This is done by turning the ignition on and lift the parking brake switch located on the center console. An amber light on the switch indicates the parking brake is activated. When instructed to "Switch the ignition On" during diagnostic testing, do not apply the brake pedal. Doing so will activate the Hybrid system. To keep the Hybrid system from arming, turn the ignition key to the right until it stops and release the key, keeping your foot OFF of the brake pedal. The ignition turns off in the same manner. Remove the key from the ignition switch after the ignition is turned off.
-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK
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% | |||
-- Switch ignition OFF.
If the specified value was Not obtained:
-- Remove the Throttle Valve Control Module -J338 - far enough so that the electrical connector terminals are accessible.
-- Disconnect the Throttle Valve Control Module -J338- electrical harness connector.
Checking voltage supply and wiring
-- Switch the ignition On.
-- Using a Multimeter check the following wiring connections for voltage.
| Throttle Valve Control Module -J338- electrical harness connector terminal | Measure To: |
|---|---|
| 2 to 6 | --- |
| 2 | Ground (GND) |
Specified value: about 5.0 V
-- Switch the ignition Off.
Continue test according to the following table:
| Value | Cause | Test |
|---|---|---|
| If the specified value was not obtained: | Open or shorted circuit | Checking wiring |
| If the specified value was obtained: | Check reference signal circuit | Checking Activation |