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Cadillac Service High Voltage

Service High Voltage

DriveNot yet established by verified evidence. One manufacturer communication reports that a vehicle may operate in reduced-power mode, but the supplied evidence does not provide a general drive/no-drive instruction.
ChargeNot yet established by verified evidence.
ServiceProfessional diagnosis is appropriate because the supplied manufacturer communications associate this alert with MIL illumination, possible reduced-power operation, and, in some cases, 12V-battery discharge. The exact service requirement is not yet established by the supplied diagnostic record.
Confidence90%

Quick answer

“Service High Voltage” is a Cadillac OEM alert. Verified evidence confirms it may appear with a malfunction indicator lamp (MIL), reduced-power operation in one manufacturer communication, or intermittent/persistent 12V-battery discharge in other communications. The specific underlying fault, driving status, charging status, and repair are not yet established by the supplied verified evidence.

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

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1. What does Service High Voltage mean?

“Service High Voltage” is a Cadillac OEM alert. Verified evidence confirms it may appear with a malfunction indicator lamp (MIL), reduced-power operation in one manufacturer communication, or intermittent/persistent 12V-battery discharge in other communications. The specific underlying fault, driving status, charging status, and repair are not yet established by the supplied verified evidence.

2. Technical explanation

This alert is a manufacturer-specific message rather than a standardized diagnostic trouble code. Cadillac manufacturer communications submitted to NHTSA describe several conditions in which a “Service High Voltage” message can appear on the instrument panel cluster. One communication states that the MIL may illuminate, the message may display, and the vehicle may operate in reduced-power mode. Separate communications state that the MIL may illuminate or the message may display while the 12V battery intermittently or persistently discharges. The supplied evidence does not identify a single cause or a universal repair for every occurrence of this message.

3. What system is affected?

High-voltage system alert; the supplied evidence also identifies possible 12V-battery discharge in certain conditions. A more specific affected component is not yet established by verified evidence.

4. How serious is this code?

Unknown. The diagnostic record lists severity as unknown. Reduced-power operation and 12V-battery discharge are documented in manufacturer communications for certain conditions.

5. Symptoms you may notice

  • “Service High Voltage” message displayed on the instrument panel cluster.
  • Malfunction Indicator Lamp (MIL) illumination.
  • Reduced-power operation, as described in NHTSA Manufacturer Communication 10253063 (PIP5961A).
  • Intermittent or persistent 12V-battery discharge, as described in PIP6021-series communications.

6. Possible causes

  • Not yet established by verified evidence. The supplied summaries confirm that manufacturer communications discuss this message under certain conditions, but do not provide sufficient verified detail to state the underlying cause.

7. Can I still drive the vehicle?

Not yet established by verified evidence. One manufacturer communication reports that a vehicle may operate in reduced-power mode, but the supplied evidence does not provide a general drive/no-drive instruction.

8. Can I charge the vehicle?

Not yet established by verified evidence.

9. What you can safely do

  • Do not attempt high-voltage system repair or disassembly.
  • Record whether the MIL is illuminated, whether reduced power is present, and whether the 12V battery is discharging.
  • Arrange professional diagnosis using the applicable Cadillac service information.

10. Step-by-step troubleshooting

  1. Have a qualified service provider retrieve diagnostic information and determine whether an applicable manufacturer communication applies.
  2. For vehicles with 12V-battery discharge, have the condition professionally evaluated in connection with the displayed alert.
  3. Do not infer a specific failed high-voltage component from this message alone; the supplied evidence does not establish one.

11. When to contact service

Professional diagnosis is appropriate because the supplied manufacturer communications associate this alert with MIL illumination, possible reduced-power operation, and, in some cases, 12V-battery discharge. The exact service requirement is not yet established by the supplied diagnostic record.

12. What the service center may check

  • Confirm the displayed message and any MIL illumination.
  • Assess whether reduced-power operation is present.
  • Assess whether the 12V battery is intermittently or persistently discharging.
  • Check applicable Cadillac manufacturer communications and service information for the vehicle.

13. Possible repair or resolution

  • Not yet established by verified evidence. The supplied manufacturer communication summaries do not provide a verified repair procedure or confirmed resolution.

14. Affected vehicles

15. Related TSBs / service bulletins

  • PIP5961A / NHTSA Manufacturer Communication 10253063, published March 6, 2024: documents that MIL illumination or a “Service High Voltage” message may occur and that the vehicle may operate in reduced-power mode. https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2020-2024.zip#nhtsa_id=10253063
  • PIP6021 / NHTSA Manufacturer Communication 11011188, published November 1, 2024: documents that MIL illumination or a “Service High Voltage” message may occur and that the 12V battery may intermittently or persistently discharge. https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2020-2024.zip#nhtsa_id=11011188
  • PIP6021A / NHTSA Manufacturer Communication 11017782, published April 29, 2025: documents that MIL illumination or a “Service High Voltage” message may occur and that the 12V battery may intermittently or persistently discharge. https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11017782
  • PIP6021B / NHTSA Manufacturer Communication 11024773, published October 30, 2025: documents that, under certain conditions, MIL illumination or a “Service High Voltage” message may display and the 12V battery may discharge. https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11024773
  • PIP6021C / NHTSA Manufacturer Communication 11034023, published June 18, 2026: documents that, under certain conditions, MIL illumination or a “Service High Voltage” message may display and the 12V battery may discharge. https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11034023
  • PIP6021D / NHTSA Manufacturer Communication 11035130, published July 13, 2026: documents that, under certain conditions, MIL illumination or a “Service High Voltage” message may display and the 12V battery may discharge. https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11035130

16. Recall information

  • Not yet established by verified evidence. No recall information was supplied.

17. Official manufacturer information

Verified applicability is for Cadillac vehicles in the United States: CELESTIQ model years 2023–2026; LYRIQ model years 2023–2026; OPTIQ model years 2023–2026; and VISTIQ model years 2023–2026. Applicability of any individual manufacturer communication is not established by the supplied summaries alone.

19. Frequently asked questions

What does “Service High Voltage” mean on a Cadillac?

It is a Cadillac OEM alert. Verified manufacturer communication summaries associate it with possible MIL illumination, reduced-power operation in one communication, and 12V-battery discharge in certain conditions. The exact fault is not yet established by verified evidence.

Can reduced power occur with this message?

Yes. NHTSA Manufacturer Communication 10253063 (PIP5961A) states that the vehicle may operate in a reduced-power mode.

Can this message be related to a 12V battery issue?

Yes. The supplied PIP6021-series communication summaries state that the 12V battery may intermittently or persistently discharge in certain conditions.

Is it safe to drive or charge?

Not yet established by verified evidence. The supplied data does not provide a general drive or charging instruction.

20. Sources & verification

Verified
Cadillac Service High Voltage: Service High Voltage | EV Diagnostics