U0007
High Speed CAN Communication Bus (-) Low
The CAN-Low line is shorted to ground or held below its valid recessive level. The differential pair cannot transmit data and the bus is effectively dead.
- 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.
- CAN-Low shorted to groundCommon
- Failed transceiver on one modulePossible
- Gateway module routing CAN messages incorrectlyLess likely
Parts involved
- CAN Low Wire
- CAN Transceiver
U0007 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.