Cadillac U0284
Lost Communication with Active Grille Air Shutter 1 Motor Module • U0285: Lost Communication with Active Grille Air Shutter 2 Motor Module • U1345: Engine Control Module LIN Bus 1
Quick answer
U0284 is documented by Cadillac bulletin 15-NA-087 as “Lost Communication with Active Grille Air Shutter 1 Motor Module.” The same bulletin evidence also lists U0285 and U1345. For 2017–2018 Cadillac CT6 vehicles in the US, these codes are among the DTCs referenced by that bulletin.
This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.
Watch Videos
Relevant videos play here without leaving this diagnostic page.
Videos are supporting material and never override OEM or regulator evidence.
1. What does U0284 mean?
U0284 is documented by Cadillac bulletin 15-NA-087 as “Lost Communication with Active Grille Air Shutter 1 Motor Module.” The same bulletin evidence also lists U0285 and U1345. For 2017–2018 Cadillac CT6 vehicles in the US, these codes are among the DTCs referenced by that bulletin.
2. Technical explanation
Verified evidence identifies U0284 as a lost-communication DTC involving Active Grille Air Shutter 1 Motor Module. The supplied official bulletin excerpt also identifies U0285 as lost communication with Active Grille Air Shutter 2 Motor Module and U1345 as Engine Control Module LIN Bus 1. The supplied excerpt does not establish diagnostic steps, a specific failure cause, or a repair for U0284.
3. What system is affected?
Active Grille Air Shutter 1 Motor Module communication. U0285 concerns Active Grille Air Shutter 2 Motor Module communication; U1345 concerns Engine Control Module LIN Bus 1.
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
- 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
- Record all stored diagnostic trouble codes and their status before clearing anything.
- Arrange professional diagnosis using the applicable Cadillac service information.
- Do not attempt high-voltage repairs; no high-voltage repair procedure is established by the supplied evidence.
10. Step-by-step troubleshooting
- The verified bulletin excerpt establishes that U0284, U0285, and U1345 may be listed together in the bulletin context.
- Specific test procedures, wiring checks, module checks, and code-setting conditions are not yet established by the supplied evidence.
11. When to contact service
Service need is not established by the supplied evidence. A Cadillac-qualified service provider can evaluate the stored codes using applicable service information.
12. What the service center may check
- Confirm whether U0284 is stored.
- Check whether U0285 and U1345 are also stored, as they are listed in the supplied official bulletin excerpt.
- Further service checks are not yet established by verified evidence.
13. Possible repair or resolution
- Not yet established by verified evidence.
14. Affected vehicles
- Cadillac CT6 · 2017–2018 · US
15. Related TSBs / service bulletins
- NHTSA Manufacturer Communication PDF 10225708, Cadillac bulletin 15-NA-087, published October 25, 2022. The supplied excerpt lists U0284, U0285, and U1345 among DTCs set. Applicability and corrective action beyond the supplied evidence are not established.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Official source: NHTSA Manufacturer Communication PDF 10225708, Cadillac bulletin 15-NA-087: https://static.nhtsa.gov/odi/tsbs/2022/MC-10225708-0001.pdf
19. Frequently asked questions
What does U0284 mean?
Verified evidence identifies U0284 as “Lost Communication with Active Grille Air Shutter 1 Motor Module.”
Which vehicle is covered by the supplied applicability evidence?
The supplied applicability evidence identifies US-market 2017–2018 Cadillac CT6 vehicles.
Are U0285 and U1345 related codes in the supplied bulletin evidence?
Yes. The official bulletin excerpt also lists U0285, for Active Grille Air Shutter 2 Motor Module communication, and U1345, for Engine Control Module LIN Bus 1.
Is it safe to drive or charge with U0284?
Not yet established by verified evidence.