Network
generic / SAE
U0009
High Speed CAN Communication Bus (-) Shorted to Bus (+)
CAN-High and CAN-Low are shorted together. The differential signal collapses to zero and the bus controller can no longer separate dominant from recessive bits, so all communication stops.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number– / 09
Possible causes
- CAN-H and CAN-L shorted together high
- Pinched harness behind a module medium
- Gateway module routing CAN messages incorrectly low
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
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 80–800 €
- Estimated time: 1–6 h
- Component: can high wire
- Component: can low wire
- Component: module connector
- MIL / check engine light
- limp mode possible
Sources
References
sae:J2012
iso:11898