EV Diagnostics
Verified EV diagnostic knowledge page

Cadillac U1616

to-Bumper coverage (Canada Base Warranty coverage), use the f

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact a Cadillac dealer or qualified service facility for diagnosis, particularly if U1616 remains Active after DTC clearing or returns. The supplied evidence references GM SI 6535777 for U1616 diagnosis.
Confidence95%

Quick answer

U1616 is verified as “Lost Communication with Image Processing Module 1 - Processor 1 on CAN Bus 8” in a Cadillac manufacturer communication. For certain non-Super Cruise vehicles, GM documentation says the referenced component wording should instead be “B174W Front View Camera - Windshield.”

This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.

Video guides

Watch Videos

Relevant videos play here without leaving this diagnostic page.

No sufficiently relevant embeddable video has been accepted for this diagnostic yet.

Videos are supporting material and never override OEM or regulator evidence.

1. What does U1616 mean?

U1616 is verified as “Lost Communication with Image Processing Module 1 - Processor 1 on CAN Bus 8” in a Cadillac manufacturer communication. For certain non-Super Cruise vehicles, GM documentation says the referenced component wording should instead be “B174W Front View Camera - Windshield.”

2. Technical explanation

The supplied official manufacturer-communication evidence identifies U1616 SYM00 as a lost-communication DTC on CAN Bus 8 involving Image Processing Module 1 - Processor 1. A January 2025 GM communication states that, on non-Super Cruise vehicles with U1615, U1616, and/or U053B, the wording “Image Processing Module 1 - Processor 1” should be replaced with “B174W Front View Camera - Windshield.” The database canonical title and meaning shown for this record are incomplete warranty-language fragments and do not establish the technical meaning of U1616. The official TSB evidence provides the verified diagnostic description above.

3. What system is affected?

Communication network / image-processing or front-view-camera-related module, as identified in the applicable GM communications. The exact component interpretation depends on whether the vehicle has Super Cruise; non-Super Cruise wording is B174W Front View Camera - Windshield.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

Not yet established by verified evidence.

6. Possible causes

  • An active U1616 is a lost-communication condition involving Image Processing Module 1 - Processor 1 on CAN Bus 8, according to the supplied manufacturer communication.
  • For non-Super Cruise vehicles, GM directs that the module wording be interpreted as B174W Front View Camera - Windshield.
  • Further root cause is not yet established by verified evidence.

7. Can I still drive the vehicle?

Not yet established by verified evidence.

8. Can I charge the vehicle?

Not yet established by verified evidence.

9. What you can safely do

  • Arrange diagnosis by a Cadillac dealer or qualified service facility if U1616 is active or recurring.
  • Do not replace a controller solely because U1616 is present when the applicable GM bulletin directs otherwise.
  • Do not perform high-voltage repair work; no high-voltage repair procedure is established by the supplied evidence.

10. Step-by-step troubleshooting

  1. The supplied PIT6503 communications instruct technicians to clear DTCs and recheck them. If U1615 and U1616 remain Active, follow GM Service Information diagnostic procedure SI 6535776 for U1615 or SI 6535777 for U1616.
  2. The same communication directs technicians to check whether B1A05 is Active in the B174W Front View Camera module after U1615/U1616 are no longer Active; the supplied excerpt does not provide the complete B1A05 procedure.
  3. For U1616 listed under PIC6500A, GM instructed dealers to verify the customer concern and not replace the controller while engineering resolution was pending. If the listed DTCs were not present, GM directed normal Service Information diagnostics.

11. When to contact service

Contact a Cadillac dealer or qualified service facility for diagnosis, particularly if U1616 remains Active after DTC clearing or returns. The supplied evidence references GM SI 6535777 for U1616 diagnosis.

12. What the service center may check

  • Read and record diagnostic trouble codes, including whether U1616 is Active.
  • Clear DTCs and recheck whether U1615 and U1616 remain Active, as directed in PIT6503.
  • If U1616 remains Active, follow GM SI 6535777, as referenced by PIT6503.
  • Determine whether the vehicle is non-Super Cruise when applying the terminology clarification in PIT6313.
  • Check for Active B1A05 in the B174W Front View Camera module when directed by the PIT6503 workflow.

13. Possible repair or resolution

  • Do not replace the controller solely based on the DTC list covered by PIC6500A; that communication directed dealers to await engineering resolution at that time.
  • The supplied evidence does not establish a final component repair for U1616.
  • Follow the applicable GM Service Information diagnostic procedure SI 6535777 when U1616 remains Active.

14. Affected vehicles

15. Related TSBs / service bulletins

  • PIT6503E, NHTSA manufacturer communication 11036709, published August 27, 2026: directs a clear-and-recheck workflow for U1615/U1616 and references SI 6535777 for active U1616.
  • PIT6503D, NHTSA manufacturer communication 11036400, published August 21, 2026: contains the same supplied U1615/U1616 active-DTC workflow excerpt.
  • PIT6457B, NHTSA manufacturer communication 11027686, published January 12, 2026: lists U1616 among related radio DTCs; no specific U1616 remedy is established by the supplied excerpt.
  • PIC6587B, NHTSA manufacturer communication 11018476, published May 13, 2025: identifies U1616 SYM00 as lost communication with Image Processing Module 1 - Processor 1 on CAN Bus 8.
  • PIT6313, NHTSA manufacturer communication 11012936, published January 7, 2025: for non-Super Cruise vehicles, replaces the Image Processing Module wording with B174W Front View Camera - Windshield for U1616, U1615, and/or U053B.
  • PIC6500B, NHTSA manufacturer communication 11007683, published September 11, 2024: lists U1616 SYM00 among covered DTCs; no specific repair is established by the supplied excerpt.
  • PIC6500A, NHTSA manufacturer communication 10237683, published May 24, 2023: instructed dealers not to replace the controller for listed DTCs including U1616 while engineering resolution was pending.

16. Recall information

No recall relationship is established by verified evidence.

17. Official manufacturer information

Verified evidence consists of NHTSA-hosted Cadillac/GM manufacturer communications. No recall evidence was supplied. Applicability in the supplied database is Cadillac CELESTIQ model years 2023–2026, LYRIQ model years 2023–2026, OPTIQ model years 2023–2026, and VISTIQ model years 2023–2026, all marked US. Individual bulletin applicability and exact vehicle configuration must be confirmed by the servicing dealer.

19. Frequently asked questions

What does Cadillac U1616 mean?

Verified GM communication PIC6587B identifies U1616 SYM00 as “Lost Communication with Image Processing Module 1 - Processor 1 on CAN Bus 8.” For non-Super Cruise vehicles, PIT6313 says this wording should be replaced with “B174W Front View Camera - Windshield.”

Should a controller be replaced for U1616?

Not solely because U1616 is stored. PIC6500A instructed dealers not to replace the controller for its listed DTCs, including U1616, while engineering resolution was pending. Current diagnosis should follow the applicable GM Service Information procedure.

What should a technician do if U1616 remains Active?

PIT6503 directs technicians to follow GM SI 6535777 for U1616 if U1616 remains Active after DTCs are cleared and rechecked.

Is it safe to drive or charge with U1616?

Not yet established by verified evidence.

20. Sources & verification

Verified
Cadillac U1616: to-Bumper coverage (Canada Base Warranty coverage),… | EV Diagnostics