Throttle Valve Control Module - GX3-, Checking

General Description

The throttle valve operation occurs by an electric motor identified as the EPC Throttle Drive -G186- located within the Throttle Valve Control Module -GX3-. It is controlled by the Engine/Motor Control Module -J623- with primary inputs from the Accelerator Pedal Module -GX2- as well as other peripheral inputs from the EPC Throttle Drive Angle Sensor 1 -G187- and the EPC Throttle Drive Angle Sensor 2 -G188-.

Note the Throttle Valve Control Module -GX3- is also referred to as the Throttle Valve Control Module -J338-.

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 they 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 automatic transmission, ensure the selector lever position is in "P".
Vehicles with manual transmission, ensure the shifter lever position is in "N" with the parking brake applied.
Observe all safety precautions: SAFETY PRECAUTIONS
View clean working conditions: CLEAN WORKING CONDITIONS

Test Procedure

NOTE:

Note the CA1 and CMC both use the ECM connector T105a, and the CA2 uses the ECM connector T105b. Both connectors are identical except for the suffix of "a" or "b". For simplicity, please use the suffix "a".

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 Throttle Valve Control Module - GX3-, CHECKING - 2 . -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. 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. -- Were Values 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 Throttle Valve Control Module - GX3-, CHECKING - 6 . -- NO: GO TO: Step 3 Throttle Valve Control Module - GX3-, CHECKING - 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. IGNITION: OFF. SPECIFIED VALUE: About 5.0 V. -- Was Value obtained?	-- YES: GO TO: Step 4 Throttle Valve Control Module - GX3-, CHECKING - 4 . -- NO: GO TO: Step 5 Throttle Valve Control Module - GX3-, CHECKING - 5 .
4	REMOVE: Engine/Motor Control Module -J623-. Refer to appropriate Service Information. CHECK: Throttle Valve Control Module -GX3- harness connector terminal 1 to the Engine/Motor Control Module -J623- harness connector terminal T105a / 27 for resistance. CHECK: Throttle Valve Control Module -GX3- harness connector terminal 3 to the Engine/Motor Control Module -J623- harness connector terminal T105a / 4 for resistance. CHECK: Throttle Valve Control Module -GX3- harness connector terminal 4 to the Engine/Motor Control Module -J623- harness connector terminal T105a / 28 for resistance. CHECK: Throttle Valve Control Module -GX3- harness connector terminal 5 to the Engine/Motor Control Module -J623- harness connector terminal T105a / 25 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 Throttle Valve Control Module - GX3-, CHECKING - 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 Throttle Valve Control Module - GX3-, CHECKING - 6 .
5	REMOVE: Engine/Motor Control Module -J623-. Refer to appropriate Service Information. CHECK: Throttle Valve Control Module -GX3- harness connector terminal 2 to the Engine/Motor Control Module -J623- harness connector terminal T105a / 7 for resistance. CHECK: Throttle Valve Control Module -GX3- harness connector terminal 6 to the Engine/Motor Control Module -J623- harness connector terminal T105a / 6 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω) -- Were Values obtained?	-- YES: GO TO: Step 6 Throttle Valve Control Module - GX3-, CHECKING - 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 Throttle Valve Control Module - GX3-, CHECKING - 6 .
6	Final Procedure Perform a road test to verify repair. -- Does the original DTC return?	-- YES: CHECK: Engine/Motor Control Module -J623- harness connector for any damaged, pushed-out pins. REPAIR: As necessary. If all electrical connections are OK: REPLACE: Engine/Motor 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.