Module loopback lost
The main board lost the loopback/heartbeat with a battery module — a communication dropout between the MBB and a module.
What it means
The main board lost the loopback/heartbeat with a battery module — a communication dropout between the MBB and a module.
Warning — Monitor the situation, may self-resolve.
Likely causes
- Transient CAN/comms noise
- A connector or harness issue on one module
- A module briefly dropping offline
What to do
- 1Isolated events are transient — monitor
- 2If it repeats on the same module, inspect that pack's connector and harness
- 3Persistent loss warrants a dealer check
Which bikes use this table
Recorded in the binary log rather than shown on the dash — every generation writes them.
Related codes
Other log file Communication (CAN) codes:
Dashboard codes for the same subsystem:
Questions
What does "Module loopback lost" mean in a Zero log?
The main board lost the loopback/heartbeat with a battery module — a communication dropout between the MBB and a module. It is written by the MBB. It is classed as warning: monitor the situation, may self-resolve.
What should I do about it?
Isolated events are transient — monitor. If it repeats on the same module, inspect that pack's connector and harness. Persistent loss warrants a dealer check.
See when this actually happened on your bike
A dash code tells you the fault; the log tells you the pack temperature, the state of charge and the ten minutes leading up to it.
Sources:
Community reference: ZeroManual wiki entry
The code and its name are transcribed from Zero's own owner manuals; the severity, category and troubleshooting notes are ours. For official diagnostics, consult an authorized Zero Motorcycles dealer.