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 Throttle Position Sensor -G69-.

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

• EPC Throttle Drive -G186-
• Throttle Position Sensor -G69-

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 electrical 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 electrical connector terminals are accessible. DISCONNECT: Throttle Valve Control Module -J338- electrical connector IGNITION: ON CHECK: Throttle Valve Control Module -J338- wiring connector pins 1 to 2 for voltage CHECK: Throttle Valve Control Module -J338- wiring 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 manual. CHECK: Throttle Valve Control Module -J338- electrical connector terminal 3 to the Engine Control Module - J623- electrical connector T105 / 26. CHECK: Throttle Valve Control Module -J338- electrical connector terminal 4 to the Engine Control Module - J623- electrical connector T91 / 84. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω) -- Was value obtained?	YES: REPLACE: Throttle Valve Control Module -J338-. Refer to appropriate repair manual. GO TO: Step 7  NO: CHECK: wiring for open, high resistance, short or electrical 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 manual. CHECK: Throttle Valve Control Module -J338- electrical connector terminal 1 to the Engine Control Module - J623- to Ground. CHECK: Throttle Valve Control Module -J338- electrical connector terminal 2 to the Engine Control Module - J623- appropriate fuse. Refer to applicable wiring diagram for fuse positions. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω) -- Was value obtained?	YES: REPLACE Engine Control Module -J623- Refer to appropriate repair manual GO TO: Step 7  NO: CHECK: wiring for open, high resistance, short or electrical 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