BYD Dolphin 2022 P1BE255: Front motor zero position not calibrated after drive motor replacement

BYD Dolphin 2022 P1BE255: Front motor zero position not calibrated after drive motor replacement

Symptoms

• In the original case, P1BE255 was read as a current fault after drive motor replacement, and zero-position calibration status showed failure. ^[1]

Diagnostic trouble codes

• P1BE255 (manufacturer): Front motor zero position not calibrated (front drive motor controller FMCU; screenshot in step 3) ^[1]

Possible causes

• This case supports incomplete zero-position calibration after motor replacement; the code does not establish damage to the new motor or motor controller. ^[1]

Checks

• Check the FMCU fault code, zero-position calibration status and motor number. A qualified technician with high-voltage repair capability must perform calibration using the original procedure and the actual vehicle manual. ^[1]

What to do

• Write the 28-character zero-position barcode from the actual vehicle motor label, confirm the calibration status and number, then recheck. The original case operated normally after code clearing and a road test; no replacement parts are recommended. ^[1]

Applicability and limits

• Only applies to the 2022 China-market Dolphin in the case credited to XTOOL Langren, requiring zero-position calibration after front drive motor replacement; do not assume applicability to overseas DOLPHIN models, other years or other drive assemblies. No vehicle model has been linked. Scope: unknown ^[1]
• After front drive motor replacement
• Diagnostic tool: BYD V13.01/FMCU
• Do not extend to other overseas DOLPHIN versions

Sources

[Source 1] Credited to XTOOL Langren Automotive Diagnostics: E2 Pro | 2022 BYD Dolphin: What to Do About a Drive Motor Fault? (2024-11-19) — Vehicle model year / fault symptoms; diagnostic steps 2–4 and screenshot in step 3; steps 5–10; verification and safety warnings (accessed 2026-11-01)
https://www.sohu.com/a/828135758_122032280