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Mercedes-Benz P0C4000

As a consequence, on vehicles with BMS30EB02, the DTC for the auxiliary assembly fuse P0E2F00 can be set. This triggers the yellow HV drive system warning message. In the ignition

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact an authorized Mercedes-Benz service provider promptly if P0C4000 or the described 12 V/HV warnings are present.
Confidence95%

Quick answer

P0C4000 is listed in Mercedes-Benz bulletin LI54.10-P-079533 as one of several fault codes that may be stored by the DC/DC converter. The verified bulletin evidence applies to 2022–2025 US-market EQB and G-Class vehicles.

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 P0C4000 mean?

P0C4000 is listed in Mercedes-Benz bulletin LI54.10-P-079533 as one of several fault codes that may be stored by the DC/DC converter. The verified bulletin evidence applies to 2022–2025 US-market EQB and G-Class vehicles.

2. Technical explanation

Official Mercedes-Benz manufacturer communications filed with NHTSA describe P0C4000 as part of a possible DC/DC-converter DTC group: P0C3B00, P0E9700, P0E5400, and P0C4000. The bulletin states that not all codes in the group are necessarily set. A second possible group is P1D0B00, P1CA000, and U011500. In some cases, an auxiliary-assembly-fuse DTC, P0E2F00, may be set on vehicles with BMS30EB02; the bulletin states that P0E2F00 triggers the yellow HV drive-system warning message.

3. What system is affected?

Verified evidence identifies the DC/DC converter as the controller that may store P0C4000. The supplied record does not establish a more specific system name.

4. How serious is this code?

Unknown. Verified evidence does not assign a severity level to P0C4000.

5. Symptoms you may notice

  • A red 12 V battery message, a white HV warning message, and an instrument-cluster warning message are described in the applicable Mercedes-Benz bulletin.
  • If initial warning messages are ignored, the bulletin states that additional warnings may appear, including a red HV warning message and a yellow HV drive-system warning message.
  • The bulletin specifically attributes the yellow HV drive-system warning message to P0E2F00 when that auxiliary-assembly-fuse DTC is set on vehicles with BMS30EB02.

6. Possible causes

  • P0C4000 may be stored by the DC/DC converter in the DTC group described by Mercedes-Benz.
  • The underlying cause of P0C4000 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

  • Do not ignore displayed red 12 V battery, HV, or HV drive-system warning messages.
  • Arrange professional diagnosis by a Mercedes-Benz service provider.
  • Do not attempt high-voltage system or DC/DC-converter repairs yourself.

10. Step-by-step troubleshooting

  1. Have a qualified Mercedes-Benz technician read and document all stored DTCs, including whether P0C4000 appears with P0C3B00, P0E9700, P0E5400, P1D0B00, P1CA000, U011500, or P0E2F00.
  2. Have the technician assess the vehicle using the applicable Mercedes-Benz bulletin LI54.10-P-079533. Further diagnostic procedure is not established by the supplied verified evidence.

11. When to contact service

Contact an authorized Mercedes-Benz service provider promptly if P0C4000 or the described 12 V/HV warnings are present.

12. What the service center may check

  • Retrieve DC/DC-converter fault memory.
  • Check whether the documented P0C4000 group is present: P0C3B00, P0E9700, P0E5400, and P0C4000.
  • Check for the additional documented group: P1D0B00, P1CA000, and U011500.
  • Determine whether P0E2F00 is present, particularly on vehicles with BMS30EB02.
  • Consult Mercedes-Benz bulletin LI54.10-P-079533.

13. Possible repair or resolution

  • Not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Mercedes-Benz LI54.10-P-079533, filed with NHTSA as Manufacturer Communication 11021800 (published August 8, 2025).
  • Mercedes-Benz LI54.10-P-079533, filed with NHTSA as Manufacturer Communication 11021970 (published August 5, 2025).
  • Mercedes-Benz LI54.10-P-079533, filed with NHTSA as Manufacturer Communication 11023154 (published September 16, 2025).
  • Mercedes-Benz LI54.10-P-079533, filed with NHTSA as Manufacturer Communication 11028815 (published February 14, 2026).
  • Mercedes-Benz LI54.10-P-079533, filed with NHTSA as Manufacturer Communication 11029977 (published March 11, 2026).

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified NHTSA manufacturer communications: LI54.10-P-079533. Source records: 11021800, 11021970, 11023154, 11028815, and 11029977.

19. Frequently asked questions

What does P0C4000 indicate on the covered Mercedes-Benz vehicles?

The verified bulletin identifies P0C4000 as a DTC that may be stored by the DC/DC converter, usually within a group that includes P0C3B00, P0E9700, and P0E5400. The precise fault definition is not established by the supplied evidence.

Does P0C4000 always occur with the other listed codes?

No. The bulletin states that not all DTCs in a listed group are triggered in every case.

Which vehicles are covered by the supplied evidence?

The supplied applicability evidence covers US-market 2022–2025 Mercedes-Benz EQB and G-Class vehicles.

Is the yellow HV drive-system warning caused by P0C4000?

The supplied bulletin specifically states that P0E2F00 can trigger the yellow HV drive-system warning message on vehicles with BMS30EB02. It does not establish that P0C4000 by itself triggers that warning.

20. Sources & verification

Verified
Mercedes-Benz P0C4000: As a consequence, on vehicles with BMS30EB02,… | EV Diagnostics