EV Diagnostics
Verified EV diagnostic knowledge page

Land Rover B1DC5

93 (High Voltage Coolant Heater #1 - No Operation) is also stored and cannot be erased, then the HVCH should be replaced. • Follow TOPIx DT

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact an authorized Land Rover service provider or another qualified EV high-voltage service facility. The verified communication directs technicians to follow TOPIx diagnostics.
Confidence95%

Quick answer

For a 2019–2023 US Land Rover Range Rover, verified Land Rover/NHTSA bulletin evidence states that B1DC5-93 means “High Voltage Coolant Heater #1 - No Operation.” If this DTC is stored and cannot be erased, the bulletin directs replacement of the high-voltage coolant heater (HVCH) following TOPIx diagnostic procedures.

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 B1DC5 mean?

For a 2019–2023 US Land Rover Range Rover, verified Land Rover/NHTSA bulletin evidence states that B1DC5-93 means “High Voltage Coolant Heater #1 - No Operation.” If this DTC is stored and cannot be erased, the bulletin directs replacement of the high-voltage coolant heater (HVCH) following TOPIx diagnostic procedures.

2. Technical explanation

The verified manufacturer communication describes an HVCH overheat-prevention event in which the heater will not operate for that drive cycle. It specifically states that if DTC B1DC5-93 is also stored and cannot be erased, the HVCH should be replaced. The supplied evidence does not establish diagnostic steps beyond following TOPIx diagnostics, nor does it establish whether every occurrence of B1DC5-93 requires replacement.

3. What system is affected?

High Voltage Coolant Heater #1 (HVCH), within the vehicle high-voltage thermal-management/heating system.

4. How serious is this code?

Unknown. The supplied verified evidence does not assign a severity level.

5. Symptoms you may notice

  • High Voltage Coolant Heater #1 may not operate for that drive cycle after an overheat-prevention event.

6. Possible causes

  • An HVCH overheat-prevention event is described in the verified manufacturer communication.
  • If B1DC5-93 remains stored and cannot be erased, the bulletin identifies the HVCH as requiring replacement.

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 qualified Land Rover service provider.
  • Have the vehicle assessed using the applicable TOPIx diagnostic procedure.
  • Do not attempt high-voltage heater repair yourself.

10. Step-by-step troubleshooting

  1. Confirm whether DTC B1DC5-93 is stored.
  2. Determine whether the DTC can be erased, using the applicable TOPIx diagnostic process.
  3. If B1DC5-93 is stored and cannot be erased, follow the manufacturer bulletin direction to replace the HVCH.

11. When to contact service

Contact an authorized Land Rover service provider or another qualified EV high-voltage service facility. The verified communication directs technicians to follow TOPIx diagnostics.

12. What the service center may check

  • Check for DTC B1DC5-93: High Voltage Coolant Heater #1 - No Operation.
  • Assess whether B1DC5-93 can be erased.
  • Follow TOPIx diagnostic procedures.
  • If B1DC5-93 cannot be erased, replace the HVCH as directed by the manufacturer communication.

13. Possible repair or resolution

  • Replace the high-voltage coolant heater (HVCH) when B1DC5-93 is stored and cannot be erased, following TOPIx diagnostic procedures.

14. Affected vehicles

15. Related TSBs / service bulletins

  • NHTSA Manufacturer Communication PDF 11007187: SFCC_AUG2024_47, published August 9, 2024. It states that if B1DC5-93 is stored and cannot be erased, the HVCH should be replaced.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified official source: NHTSA Manufacturer Communication PDF 11007187, “SFCC_AUG2024_47,” published 2024-08-09: https://static.nhtsa.gov/odi/tsbs/2024/MC-11007187-0001.pdf

19. Frequently asked questions

What does B1DC5-93 mean?

The verified manufacturer communication identifies B1DC5-93 as “High Voltage Coolant Heater #1 - No Operation.”

What does the bulletin say if B1DC5-93 cannot be erased?

It directs replacement of the high-voltage coolant heater (HVCH), with TOPIx diagnostics followed.

Which vehicles are covered by the supplied applicability evidence?

2019–2023 Land Rover Range Rover vehicles in the US.

Can I drive or charge with B1DC5-93?

Not yet established by verified evidence.

20. Sources & verification

Verified
Land Rover B1DC5: 93 (High Voltage Coolant Heater #1 - No Operation)… | EV Diagnostics