Zero Motorcycle Error Codes
The numeric dash codes from Zero's own owner manuals — 64 Gen2 and 65 Gen3 — plus 41 MBB and BMS log messages, with what each one means and what to do about it.
Two things this page is not. It is not a complete list of Zero fault codes: the 2026 light line (LS1, XE, XB) uses a separate b### namespace of 103 codes that lives on the bike guides instead. And the 41 log messages are a hand-picked selection, not a taxonomy — Zero writes far more strings than that.
TL;DR
Most error codes are informational or warnings that self-resolve. Critical errors (red) require immediate attention. MBB errors relate to motor/controller, BMS errors relate to battery. Use the search below to find specific codes and their solutions.
Understanding Error Severity
Normal operation events. No action required.
Monitor the situation. Often self-resolves.
Issue detected. May affect performance.
Serious issue. Immediate attention required.
Error Sources
MBB (Main Bike Board)
Errors from the central controller:
- • Motor and drivetrain issues
- • Sevcon controller faults
- • System-level problems
- • Communication errors
- • Thermal management
BMS (Battery Management System)
Errors from the battery controller:
- • Cell voltage issues
- • Battery temperature alerts
- • Charging problems
- • State of charge errors
- • Cell balance warnings
Generation Differences
Important: Error codes have different meanings between Gen2 and Gen3 motorcycles! The same code number can mean completely different things. Always filter by your generation.
Gen2 · Sevcon dash
Models: S, SR, DS (2014-2023), DSR (2016-2023), FX (2014-2025), FXS (2016-2021), FXE (2022-2025)
Codes 00-63, Sevcon Gen4 controller
- • 07: Low Battery Voltage
- • 27: Precharge Error
- • 45: Kickstand Switch Disable
- • 32: Module Variance Too High (cell balance)
Gen3 · FST / Cypher III dash
Models: SR/F and SR/S (2020+), DSR/X (2023+), S/F, and the S, SR, DS and DSR from 2024, when those four moved to the FST platform
Codes 1-99, Cypher III controller
- • 7: Mode Fault (reinstall ride modes!)
- • 27: 12V Low Voltage Fault
- • 41 / 57: Motor / Controller High Temperature
- • 29: HVIL Open (HV interlock)
Careful with 2024 and later. The S, SR, DS and DSR kept their names when they moved from the Sevcon dash to Cypher III, so the model name alone does not tell you which table to read — the year does. Codes 12 to 15 are a good example of why it matters: on a Gen3 dash 12, 13 and 15 are traction and stability control, but 14 is the right turn signal, not a traction fault.
Types of Error Codes
Dashboard Codes
Numeric codes shown on your motorcycle's dashboard display. Switch to error code display mode to see active codes.
- • Gen2: Codes 00-63 (64 defined)
- • Gen3: Codes 1-99 (65 rows — 1-66 individually, 67-99 folded into one generic fault)
- • Some are safety interlocks (normal)
- • Others indicate system issues
Log File Errors
Conditions the MBB and BMS record in the log rather than putting on the dash. They carry more detail than a two-digit code.
- • Controller Fault, Sevcon CAN Fault
- • BMS Cell Imbalance Warning
- • Pack Over Temperature
- • Isolation Fault
Unlike the dash tables, these 41 entries are hand-maintained descriptive names for conditions, compiled from the ZeroManual wiki and our own fleet mining — not verbatim strings lifted out of a log file. Searching your own log for one of them may find nothing even when the condition is present. To match the raw text a Zero actually writes, use the log error catalog, which matches signatures against it directly.
Error Code Reference
Search for specific error codes, filter by severity or source, and find troubleshooting steps. Use the filters to switch between dashboard codes (Gen2 00-63, Gen3 1-99) and log file errors. Gen3 codes are not zero-padded: search 7, not 07.
What this list does not cover. Zero's 2026 light line (LS1, XE, XB) uses a different scheme entirely — 103 codes in a b### C### P### I### namespace, with different meanings on different models. Those tables live on each machine's bike guide instead. The log-file error list below is a curated subset of what Zero writes, not a complete taxonomy — see the log error catalog for how we group the rest.
00No Error
01High Throttle
02Motor Temperature Warning Stage 1
03Motor Temperature Warning Stage 2
04Controller Temperature Warning Stage 1
05Controller Temperature Warning Stage 2
06BMS Throttle Enable Wire Error
07Low Battery Voltage
08High Battery Temperature Status
09Low Battery Temperature Status
10Battery Temperature Warning Stage 1
11Battery Temperature Warning Stage 2
12Reserve Partition Warning
13Reserve Switch Warning
14Safety Override Active
15Charger Attached But Not Charging
16CIB Contactor Compromised
17Charger Error
18Battery Temperature Sensor Fault
19High Charge Current
20BMS Low Isolation
21Board Vpack Error
22Board Temperature Error
23Post Error
24Startup Error
25Contactor Open Warning
26Contactor Welded Error
27Precharge Error
28BMS Isolation Fault
29BMS Isolation Danger
30BMS CAN Error
31SEVCON CAN Error
32Module Variance Too High
33SEVCON Error Turn Off
34Charge Error Turn Off
35Loopback Error
36Board 5V Error
37Board 3.3V Error
38Idle Turn Off
39Throttle Out Of Range Disable
40BMS Throttle Enable Wire Disable
41Low Battery Voltage Disable
42High Battery Temperature Status Disable
43Low Battery Temperature Status Disable
44Kill Switch Disable
45Kickstand Switch Disable
46BMS Charger Connected Disable
47MBB Charger Connected Disable
48SEVCON Startup Disable
49Contactor Open Disable
50BMS Self-Test Error
51BMS Self-Test Warning
52Reserve Partition Disable
53BMS Internal Disable
54Internal Disable Error
55Internal Fault Error
56Monolith Not Connected
57Module Did Not Connect
58BMS Sensor Warning
59BMS System Warning
60Bike Configuration
61Tipover Detected
62Target Magnet Warning
63Target Magnet Disable
1High Throttle Fault
2Torque Fault
3Torque Fault
4Throttle Fault
5CAN Fault
6Mode Fault
7Mode Fault
8Firmware Update Failure
9Controller Fault
10Firmware Update Failure
11Right Turn Signal Short Fault
12Traction Control Fault
13Traction Control Fault
14Right Turn Signal Bulb Out Fault
15Stability Control Fault
16Headlight Short Fault
17Headlight Bulb Out Fault
20Brake Bulb Short Fault
21Brake Bulb Out Fault
2212V Battery Heater Short Fault
2312V Battery Heater Disconnect Fault
2412V Battery Reversed
2512V Battery Low
26DC-DC Low
2712V Low Voltage Fault
2812V Low Voltage Fault
29HVIL Open Fault
30Self Test Fail
31Battery Module Ineligible
32Contactor Open
33Battery Module Awaiting Connection
34Battery Module Connection Retries Fault
35Pilot Signal Invalid Fault
36Region Invalid Fault
37Charger Not Connected
38Charger Fault
39Immobilizer Disconnected
40Immobilizer Fault
41Motor High Temperature
42Heated Grip Fault
43Isolation Fault
44Memory Fault
45Memory Fault
46Memory Fault
47Memory Fault
48Memory Fault
49Battery Module Incompatible
50Battery Module Features Not Supported
51Battery Pack Voltage Too High
52Battery Pack Voltage Too Low
53Power Pack Voltage Low
54Battery Voltage Low
55Battery Temperature High
56Battery Temperature Low
57Controller High Temperature
58Battery Fault
59Heated Grip Fault
60CCS Converter Fault
61CCS Interface Fault
62CCS Communication Fault
63Left Turn Signal Short Fault
64Left Turn Signal Bulb Out Fault
65Charger Fan Fault
66Ignition Fault
67-99Motorcycle Fault
Controller FaultGeneral Sevcon controller fault detected
Sevcon CAN FaultCommunication lost with Sevcon motor controller
Motor Over TemperatureMotor temperature exceeds safe operating limit (typically >100°C)
Controller Over TemperatureSevcon controller temperature exceeds limit (typically >80°C)
Pack Over TemperatureBattery pack temperature exceeds safe limit (typically >45°C)
Pack Under TemperatureBattery pack temperature too low for charging (typically <0°C)
Cell Voltage HighOne or more cells exceeded maximum voltage (>4.25V)
Cell Voltage LowOne or more cells dropped below minimum voltage (<3.0V)
Cell ImbalanceCell voltage delta (B field) exceeds threshold (typically >100mV)
BMS Communication LostMain bike board lost communication with battery management system
Charger Communication LostCommunication lost with onboard charger module
Charge Tank Communication LostCommunication lost with optional Charge Tank module
12V Battery LowAuxiliary 12V battery voltage is low
Precharge FailedHigh-voltage system precharge sequence failed
Contactor StuckMain battery contactor is welded or stuck closed
Motor Phase FaultIssue detected with motor phase wiring or windings
Motor Hall Sensor FaultMotor position sensor (Hall effect) signal invalid
Throttle FaultThrottle position sensor reading invalid
Kickstand DownKickstand is deployed - bike will not move
Kill Switch ActiveMotor kill switch is in OFF position
ChargingBattery is actively charging
Charged To FullBattery has reached 100% state of charge
Charge Current LimitedBMS has reduced charging current
Discharge Current LimitedBMS has reduced maximum discharge current (power limiting)
Power LimitedController has reduced available power due to thermal derating
Module OfflineA battery module is not responding (multi-module bikes)
ISO FaultInsulation fault detected - high voltage may be contacting chassis
Limp ModeBike is operating in reduced-power safety mode
Firmware MismatchModule firmware versions are incompatible
Regen LimitedRegenerative braking reduced or disabled
Accelerometer Selftest FailedThe onboard accelerometer (used for tip-over / lean sensing) failed its power-on self-test and is retrying. Logged as 'Accelerometer Selftest Failed, retrying...'.
Module loopback lostThe main board lost the loopback/heartbeat with a battery module — a communication dropout between the MBB and a module.
Dtc set because of bms can errorThe main board set a diagnostic trouble code because it hit a CAN communication error talking to a BMS.
Bluetooth module reset (RN-42)The onboard Bluetooth module (RN-42) did not exit command mode and was reset via its reset pin — a benign comms retry. Logged as 'Turn off command mode on RN-42 failed after N retries, toggling reset pin'.
Quick Self Test ErrorThe BMS power-on quick self-test flagged a subsystem before going online — e.g. cell measurement ('Cells Failed') or the pack-I/O ADC ('PackIO ADC Failed').
SelfTest finished with warningsThe BMS completed its self-test but raised one or more non-fatal warning flags (a bitfield) — noted diagnostics rather than a hard failure.
Startup Failed with codeA BMS startup step failed and reported an error code (e.g. 'Startup Failed with code -6'); the controller typically retries the sequence.
Attempting to recover from Charge FaultAfter a charge fault the BMS is retrying to resume charging — a normal recovery step, not a hard stop.
Settings Read Failed / Reset to DefaultsStored settings could not be read and were reset to defaults — internal housekeeping, sometimes after a firmware update. Logged as 'Settings Read Failed, Resetting All Settings to Defaults'.
Watchdog extended for bootloaderThe firmware extended the watchdog window so the bootloader has time to start — a normal part of the boot / firmware-update sequence. Logged as 'Setting watchdog timeout to N seconds to allow bootloader time to start...'.
Watchdog Timer Reset (WDT Timeout)A controller's watchdog timer expired and reset the processor — the firmware stopped servicing the watchdog (a hang or overrun); a stack trace is logged.
Every code, on its own page
All 170 entries above also have a dedicated page with the meaning, the severity, the likely causes and what to do — plus, for a dash code, what the SAME number means on the other generation's dash. Each chip is tinted by its own severity, so hovering is not the only way to tell a critical code from a normal one.
Gen2 · Sevcon dash — codes 00-63 (64)
Gen3 · Cypher III dash — codes 1-99 (65)
Log file conditions (41)
When to Worry (and When Not To)
Usually Not a Problem
- • Single occurrence of a warning
- • Temperature warnings that resolve with cooling
- • Charge Tank communication errors (if not installed)
- • "Power Limited" during heavy use in hot weather
- • "Regen Limited" at high SOC
Contact Dealer
- • Any critical (red) error
- • Recurring errors that don't resolve
- • Cell voltage errors (high or low)
- • ISO fault or insulation warnings
- • Contactor stuck errors
- • BMS communication lost
Quick Troubleshooting Steps
Turn off the bike, wait 30 seconds, and turn it back on. Many transient errors clear this way.
Ensure all visible connectors are secure. Communication errors often stem from loose connections.
A weak 12V battery can cause various system errors. Test voltage and replace if needed.
Thermal errors will resolve once temperatures normalize. Park in shade and wait 15-30 minutes.
Extract and analyze your logs to see the full error history and context. This tool can help!
Sources:
The dashboard tables above are transcribed from Zero's own owner manuals; the severity, category and troubleshooting notes are ours, and the log-file error list is compiled from community sources and our own fleet log mining. For official diagnostics, always consult an authorized Zero Motorcycles dealer.