Electronic Throttle Control Module: Testing and Inspection

Throttle Valve Control Module, Checking

Special tools, testers and auxiliary items 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.

Test procedure

- Observe safety precautions. Refer to => [ Safety Precautions ] Safety Precautions

- Observe Clean Working Conditions. Refer to => [ Clean Working Conditions ] Clean Working Conditions

- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check.

Start diagnosis

Function

Throttle valve operation occurs by an electric motor ( Throttle Drive (for Electronic Power Control (EPC)) (G186) ) located in the Throttle Valve Control Module (J338). It is controlled by the Engine Control Module (ECM) (J623) according to input from the Accelerator Pedal Position Sensor 1 (G79) / Accelerator Pedal Position Sensor 2 (G185) as well as other inputs.

Components of Throttle Valve Control Module (J338) :

• Throttle Drive (for Electronic Power Control) (G186)

• Throttle Drive Angle Sensor 1 (G187)

• Throttle Drive Angle Sensor 2 (G188)

Function test

- Connect the scan tool.

- Switch ignition On.

- Using the scan tool, check the throttle valve position (absolute) at idle stop:






- 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:






- 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 Valve Control Module (J338) terminals 3 to 5 for resistance.

Specified value: 1.0 to 5.0 ohms (at 20° C)

If the specification was Not obtained:

- Replace the Throttle Valve Control Module (J338). Refer to the repair information.

If the specification was obtained:

Checking voltage supply and wiring

- Switch the ignition On.

- Using a multimeter, check 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.

- Using a multimeter, check the Throttle Valve Control Module (J338) electrical harness connector terminals to the Engine Control Module (ECM) (J623) electrical harness connector T60 terminals for an open circuit.






Specified value: 1.5 ohms max.

If the specification is not obtained:

- Check the wiring for high resistance, an open or a short to voltage or ground.

- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring, the resistance check was OK but the voltage check was Not 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 mentioned sequence:

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.