Throttle Valve Control Module Checking
Use only gold-plated terminals when servicing terminals in harness connector of this system.
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 Electronic Power Control (EPC) -G186- in Throttle Valve Control Module - J338-. It is operated by Engine Control Module (ECM) -J623- according to specifications of Throttle Position (TP) Sensor -G79-/Accelerator Pedal Position Sensor 2 -G185 -.
Components of Throttle Valve Control Module -J338-:
- Throttle Drive 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 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 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.
Checking resistance
-- Using a multimeter, check the Throttle Drive 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:
Checking voltage supply
-- Switch the ignition On.
-- Using a multimeter, check the Throttle Drive Electronic Power Control (EPC) -G186- at the Throttle Valve Control Module -J338- electrical harness connector terminals 2 to 6 for voltage.
Specified value: at least 4.5 V
-- Switch the ignition Off.
If the specified value was obtained:
-- Replace the Throttle Valve Control Module - J338-.
If the specified value was Not obtained:
Checking wiring
If the manufacturers test box is being used. Perform the following step.
-- Install the test box.
If the manufacturers test box is not being used. Perform the following step.
-- Remove the Engine Control Module (ECM) -J623-. Refer to the Repair Information.
-- Using a multimeter, check the Throttle Drive Electronic Power Control (EPC) -G186- at Throttle Valve Control Module -J338- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T121 terminals for resistance.
| Throttle Valve Control Module -J338- electrical harness connector terminals | Engine Control Module (ECM) -J623- electrical connector T121 terminals or test box sockets |
|---|---|
| 1 | 92 |
| 2 | 83 |
| 3 | 117 |
| 4 | 84 |
| 5 | 118 |
| 6 | 91 |
Specified value: 1.5 Ω max.
If the specification is Not obtained:
-- Check the wiring for an open circuit, high resistance, a short circuit to each other, Battery (+) or Ground.
-- If necessary, repair the faulty wiring connection.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
If no malfunction is found in the wiring and the voltage supply was not OK:
-- Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
-- Perform a road test to verify repair.
If the DTC does not return:
Generate readiness code. Refer to READINESS CODE .
If the DTC returns, no malfunction is found in the wiring and the voltage supply was OK:
-- Replace the Engine Control Module (ECM) -J623-. Refer to the Repair Information.
-- Assembly is performed in the reverse of the removal.
Final procedures
After repair work, the following work steps must be performed in the following sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .