GM HMI 2.5 No Video Troubleshooting

GM HMI 2.5 Black Screen / No Video Troubleshooting

Important

This guide applies specifically to the Bosch NG 2.5 HMI used in supported GM infotainment systems. It is intended for customers who have reinstalled an HMI that was repaired by UpFix and are still experiencing a black screen or no-video condition.

UpFix function-tests the repaired HMI in our reference test rig and records a video showing the unit operating before it is returned. If the same symptom remains after installation, follow the checks below before assuming the repaired HMI is still faulty.

If the display produces a normal picture but has unresponsive touch, dead spots, or ghost touch, that is a separate information display/touchscreen issue and is not corrected by the HMI repair.

This repair listing is only for the NG 2.5 HMI. NG 2.0 and NG 1.1 modules are not covered by this repair listing.

What This Repair Addresses

This repair is intended for:

• Black screen / no video caused by an internal NG 2.5 HMI failure

If the repaired HMI has been reinstalled and the vehicle still has no video, follow the checks below before assuming the HMI is still faulty.

Step 1: Confirm the Original Symptom and Review the Test Video

Verify that the vehicle still has the same black-screen or no-video condition that the HMI was originally sent in for.

Compare the vehicle condition with the UpFix test video and note:

• Whether the display is completely black or appears backlit/gray
• Whether audio is still heard from the radio
• Whether any image appears at startup or at any time
• Whether the screen still responds to touch or gives haptic/feedback response, if equipped
• Whether the symptom is constant or intermittent

A different symptom after installation may indicate a separate vehicle-side issue rather than the original HMI failure.

Step 2: Confirm the Correct Repaired HMI Was Reinstalled

Verify that the original repaired module was installed back into the vehicle.

Check:

• The label clearly identifies the module as NG 2.5 HMI
• The repaired HMI returned by UpFix is the unit currently installed
• No connector was left disconnected during installation
• No similar HMI, radio, or display module was accidentally substituted

GM used multiple HMI generations that look very similar. A physically similar NG 1.1 or NG 2.0 module is not the same application as the NG 2.5 HMI.

Step 3: Perform a Complete HMI Power Cycle

After installation, allow the vehicle and infotainment system to complete a full power-down and restart.

If the display remains blank, use the vehicle-specific service information to power-cycle the HMI/infotainment circuit. On applicable GM systems, this may involve removing the correct HMI fuse for several minutes, reinstalling it, and then rechecking operation.

Do not remove random fuses or disconnect modules with the ignition on. If you are unsure which fuse supplies the HMI, use the vehicle wiring diagram or have a qualified technician perform this step.

A module that has not completed a proper power cycle may remain unresponsive even when the repaired HMI itself is functional.

Step 4: Check Battery Voltage and Infotainment Fuses

Low system voltage or a missing power feed can prevent the HMI, radio, or information display from starting correctly.

Check:

• Battery voltage
• Charging-system voltage with the engine running
• HMI / infotainment-related fuses
• Radio-related fuses
• Information display/screen related fuses, where applicable

Test fuses with a meter or test light rather than relying only on visual inspection.

A blown fuse, weak power supply, or low-voltage condition will not be corrected by repairing the HMI.

Step 5: Inspect the HMI, Display, and Video Cable Connections

Verify that all connectors disturbed during removal and installation are fully seated and locked.

Inspect for:

• Bent or damaged pins
• Backed-out or loose terminals
• Corrosion, moisture, or contamination
• Damaged connector locks
• Pinched or damaged wiring
• Connectors that are not fully seated

Pay particular attention to the video/display cable between the HMI and the information display. GM service information may refer to this as the USB video cable on these systems. Reseat the cable at both ends and inspect it for damage.

A poor video cable or display connection can create the same black-screen symptom as an internal HMI failure.

Step 6: If the Screen Is Black but Audio Still Works

If the display is blank but the radio still produces audio, the entire infotainment network is not necessarily down.

Focus diagnosis on:

• The video/display cable between the HMI and information display
• The information display itself
• The display connector and terminal fit
• Display power and ground, where applicable

If the screen still responds to touch or provides feedback while the picture is missing, this is additional evidence that the problem may be in the video/display path rather than a completely non-operational HMI.

If available, testing with a known-good display or known-good video cable can help isolate the fault before the repaired HMI is condemned.

Step 7: If the Screen Is Black and There Is No Audio

If the vehicle has both a blank display and no audio, diagnose the complete infotainment system rather than the HMI alone.

Check for:

• Loss of power or ground to the HMI or radio
• Infotainment network / MOST communication faults
• A radio or another infotainment module that is offline
• Damaged wiring or connectors that may be affecting the network

On applicable GM systems, a module, connector, or wiring fault can bring the infotainment communication network down and cause both no display and no audio.

Step 8: Separate Touchscreen Problems From Video Problems

If the display now produces a normal picture but the touchscreen does not respond correctly, the remaining concern is not the black-screen/no-video HMI repair.

Examples of information-display / digitizer problems include:

• Unresponsive touch
• Dead spots or areas that do not respond
• Ghost touch or inputs occurring without being pressed

These conditions require a separate information display/touchscreen repair service.

Step 9: Scan the Infotainment System for Fault Codes

Use GDS2 or another scan tool capable of accessing the vehicle's infotainment modules.

Check the:

• HMI module
• Radio/infotainment module
• Information display/control module, where applicable
• Infotainment communication network

Record all current and history DTCs before clearing anything. Communication codes, including MOST-bus related codes on applicable vehicles, can help identify a vehicle-side network, module, or wiring problem.

Do not reprogram the repaired HMI unless UpFix specifically directs you to do so.

Step 10: If the Vehicle Still Has a Black Screen / No Video

If all of the following have been verified:

• The repaired NG 2.5 HMI shown working in the UpFix test video is installed
• Battery voltage and applicable fuses are good
• HMI power and ground are present
• HMI and display connectors are fully seated and undamaged
• The video/display cable has been inspected or tested
• The information display has been checked
• Infotainment DTCs and network faults have been checked

If the vehicle still has the same black-screen / no-video condition, contact UpFix for additional assistance.

Please provide the vehicle VIN, whether audio is present, any stored DTCs, and the results of the checks above.

Do not open, disassemble, replace, or reprogram the repaired HMI before contacting UpFix.

Additional vehicle-side diagnosis may be required before determining that the repaired HMI is responsible for the remaining issue.