Throttle Valve Control Module -J338-, CHECKING

Function

Throttle valve operation occurs by an electric motor identified as EPC Throttle Drive -G186- located within the Throttle Valve Control Module - J338-. It is controlled by the Engine Control Module - J623- with primary inputs from the Accelerator Pedal Position Sensor -G79- / Accelerator Pedal Position Sensor 2 -G185- as well as other peripheral inputs from EPC Throttle Drive Angle Sensor 1 -G187- and EPC Throttle Drive Angle Sensor 2 -G188-.

The Throttle Valve Control Module -J338- contains the following components:

EPC Throttle Drive -G186-
EPC Throttle Drive Angle Sensor 1 -G187-
EPC Throttle Drive Angle Sensor 2 -G188-

The Throttle Valve Control Module -J338- components cannot be serviced separately, it must be serviced as a unit.

Special tools and workshop equipment required

Multimeter.
Wiring diagram.
Scan tool.

Test requirements

Fuses OK.
Battery voltage OK.
Switch OFF All electrical and electronic accessories.
Vehicles with Auto. Transmission, ensure Selector Lever position is in "P".
Vehicles with Manual Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
Coolant Temperature: ≥ 80° C.
Observe all safety precautions: SAFETY PRECAUTIONS .
View clean working conditions: CLEAN WORKING CONDITIONS .

Test Procedure

Step	Procedure	Result / Action to Take
1	PERFORM: Preliminary Check to verify the customers complaint. Refer to PRELIMINARY CHECK . -- Was complaint verified?	YES: GO TO Step 2. NO: GATHER more information from customer about the complaint.
2	CONNECT: Scan Tool. IGNITION: ON. CHECK: Throttle valve position closed. SPECIFIED VALUE: 3 - 25%. DEPRESS: Accelerator pedal slowly to WOT while observing the percentage display. The percentage display must increase uniformly. CHECK: Throttle valve position at WOT. SPECIFIED VALUE: 84 - 97%. IGNITION: OFF. -- Was value obtained?	YES: GO TO Step 3. NO: GO TO Step 4.
3	Condition may be intermittent. PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector.	GO TO: Step 7.
4	REMOVE: Throttle Valve Control Module -J338 - far enough so that the harness connector terminals are accessible. DISCONNECT: Throttle Valve Control Module -J338- harness connector. IGNITION: ON. CHECK: Throttle Valve Control Module -J338- harness connector pins 2 to 6 for voltage. CHECK: Throttle Valve Control Module -J338- harness connector pin 2 to ground for voltage. SPECIFIED VALUE: About 5.0 V. IGNITION: OFF. -- Was value obtained?	YES: GO TO Step 5. NO: GO TO Step 6.
5	REMOVE: Engine Control Module - J623-. Refer to appropriate service information. CHECK: Throttle Valve Control Module -J338- harness connector terminal 1 to the Engine Control Module - J623- harness connector T105 / 27 for resistance. CHECK: Throttle Valve Control Module -J338- harness connector terminal 4 to the Engine Control Module - J623- harness connector T105 / 28 for resistance. CHECK: Throttle Valve Control Module -J338- harness connector terminal 3 to the Engine Control Module - J623- harness connector T105 / 4 for resistance. CHECK: Throttle Valve Control Module -J338- harness connector terminal 5 to the Engine Control Module - J623- harness connector T105 / 25 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were values obtained?	YES: REPLACE: Throttle Valve Control Module -J338-. Refer to the appropriate repair information. GO TO: Step 7. NO: CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 7.
6	REMOVE: Engine Control Module - J623-. Refer to appropriate service information. CHECK: Throttle Valve Control Module -J338- harness connector terminal 2 to the Engine Control Module - J623- harness connector T105 / 7 for resistance. CHECK: Throttle Valve Control Module -J338- harness connector terminal 6 to the Engine Control Module - J623- harness connector T105 / 6 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Was value obtained?	YES: REPLACE Engine Control Module -J623-. Refer to the appropriate repair information. GO TO: Step 7. NO: CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 7.
7	Final Procedure Perform a road test to verify repair. Do any DTC's return:	YES: Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY . Perform the diagnostic procedure for that DTC. NO: Repair is complete. Generate readiness code. Refer to READINESS CODE . Return vehicle to Customer.