Throttle Valve Control Module - GX3-, Checking

General Description

Throttle valve operation occurs by an electric motor identified as EPC Throttle Drive -G186- located within the Throttle Valve Control Module -GX3-. It is controlled by the Engine Control Module - J623- with primary inputs from the Accelerator Pedal Module -GX2- 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 -GX3 / 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 -GX3 / J338- components cannot be serviced separately, and 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.
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: 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 6. -- NO: GO TO: Step 3.
3	REMOVE: Throttle Valve Control Module - GX3- far enough so that the harness connector terminals are accessible. DISCONNECT: Throttle Valve Control Module - GX3- harness connector. IGNITION: ON. CHECK: Throttle Valve Control Module - GX3- harness connector terminals 2 to 6 for voltage. SPECIFIED VALUE: About 5.0 V. IGNITION: OFF. -- Were Values obtained?	-- YES: GO TO: Step 5. -- NO: GO TO: Step 4.
4	REMOVE: Engine Control Module - J623-. Refer to appropriate Service Information. CHECK: Throttle Valve Control Module - GX3- harness connector terminal 2 to the Engine Control Module - J623- harness connector T105 / 30 for resistance. CHECK: Throttle Valve Control Module - GX3- harness connector terminal 6 to the Engine Control Module - J623- harness connector T105 / 9 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: GO TO: Step 6. -- NO: 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 6.
5	REMOVE: Engine Control Module - J623-. Refer to appropriate Service Information. CHECK: Throttle Valve Control Module - GX3- harness connector terminal 1 to the Engine Control Module - J623- harness connector T105 / 31 for resistance. CHECK: Throttle Valve Control Module - GX3- harness connector terminal 3 to the Engine Control Module - J623- harness connector T105 / 45 for resistance. CHECK: Throttle Valve Control Module - GX3- harness connector terminal 4 to the Engine Control Module - J623- harness connector T105 / 10 for resistance. CHECK: Throttle Valve Control Module - GX3- harness connector terminal 5 to the Engine Control Module - J623- harness connector T105 / 46 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: REPLACE: Throttle Valve Control Module - GX3-. Refer to appropriate Service Information. GO TO: Step 6. -- NO: 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 6.
6	Final Procedure Perform a road test to verify repair. -- Does the original DTC return?	-- YES: CHECK: Engine Control Module -J623- harness connector for any damaged, pushed-out pins. REPAIR: As necessary. If all electrical connections are OK: REPLACE: Engine Control Module -J623-. Refer to appropriate Service Information. Clear the DTC's. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY . Repair is complete. Generate Readiness Code. Refer to READINESS CODE . Return vehicle to Customer. -- NO: Perform the diagnostic procedure for any DTC's. If no DTC's return the repair is complete. Return vehicle to customer.