Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pinpoint Test G: U0103:00
- Refer to MODULE COMMUNICATIONS NETWORK
for schematic and connector information.
Normal Operation and Fault Conditions
The IPMA communicates with GSM through the FD-CAN, GWM and HS-CAN2.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition IPMA U0103:00 Lost Communication With Gear Shift Control Module A: No Sub Type Information A continuous memory DTC that sets in the IPMA if messages received from the GSM through the GWM are missing. Possible Sources
- Communication network concern
- GSM
- IPMA concern
- GWM
- G1 VERIFY THE CUSTOMER CONCERN
- Ignition ON.
- Verify there is an observable symptom present.
Is an observable symptom present?
Yes GO to G2 No CLEAR the DTC. The system is operating normally at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - G2 CHECK THE COMMUNICATION NETWORK
- Using a diagnostic scan tool, perform the network test
Does the GSM pass the network test?
Yes GO to G3 No REFER to: Controller Area Network (CAN) Module Communications Network . REFER to: Ethernet Module Communications Network . - G3 PERFORM THE IPMA (IMAGE PROCESSING MODULE A) SELF-TEST
- Using a diagnostic scan tool, perform the IPMA self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes DIAGNOSE all non-network Diagnostic Trouble Codes (DTCs). REFER to the IPMA DTC Chart. No GO to G4 - G4 PERFORM THE GSM (GEAR SHIFT MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the GSM self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?
Yes DIAGNOSE all non-network Diagnostic Trouble Codes (DTCs). REFER to: Cruise Control . No GO to G5 - G5 PERFORM THE GWM (GATEWAY MODULE A) SELF-TEST
- Using a diagnostic scan tool, perform the GWM self-test.
Are any Diagnostic Trouble Codes (DTCs) set?
Yes REFER to: Controller Area Network (CAN) Module Communications Network . REFER to: Ethernet Module Communications Network . No GO to G6 - G6 RECHECK THE IPMA (IMAGE PROCESSING MODULE A) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, clear the IPMA Diagnostic Trouble Codes (DTCs).
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Using a diagnostic scan tool, perform the continuous memory self-test.
- Check the IPMA Diagnostic Trouble Codes (DTCs).
Is DTC U0103:00 still present?
Yes GO to G7 No The system is operating correctly at this time. The DTC may have set due to high network traffic or an intermittent fault condition. - G7 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERNNOTE: If new modules were installed prior to the DTC being set, the module configuration may be incorrectly set during the PMI, or the PMI may not have been carried out.
- CHECK the vehicle service history for recent service actions related to the GSM, IPMA or GWM. If recent service history is found:
- verify correct replacement module was installed
- HVBOM may be used to verify correct part fitment
- verify the configuration of replacement module was correct
- re-configure module using as-built data if prior configuration is suspect
- verify the module was not obtained from a like vehicle and installed into customer vehicle
- return the swapped module to source vehicle and obtain new replacement module
- verify correct replacement module was installed
- Operate the system and determine if the observable symptom is still present.
Is the observable symptom still present?
Yes GO to G8 No The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration. - CHECK the vehicle service history for recent service actions related to the GSM, IPMA or GWM. If recent service history is found:
- G8 CHECK FOR CORRECT GSM (GEAR SHIFT MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all GSM connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect the GSM connectors. Make sure they seat and latch correctly.
- Operate the system to determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new GSM. REFER to: Gear Shift Module (GSM) - Vehicles With: Column Shift . REFER to: Gear Shift Module (GSM) - Vehicles With: Console Shift . No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.