U0024
Low Speed CAN Communication Bus Off
The low-speed CAN controller has gone bus-off after repeated error frames. The fault-tolerant single-wire fallback is exhausted and the bus stops carrying traffic.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
Ordered by how often each turns out to be the cause.
- Wiring short keeps bus in bus-offCommon
- One failing node spamming errorsPossible
- Gateway module routing CAN messages incorrectlyLess likely
Parts involved
- Low Speed CAN Wiring
- Body Control Module
U0024 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.