OBD-II code · Network
U0005 High Speed CAN Communication Bus (+) High
The CAN-High line is held above its valid voltage range, usually because of a short to battery voltage. Bus communication collapses for every connected module.
Is it safe to drive with U0005?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyCAN-High shorted to battery voltage
- PossibleChafed harness against power wire
- Less likelyGateway module routing CAN messages incorrectly
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
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–6 h
- Emissions test
- Usually unaffected
- Parts involved
- Can High Wire, Module Connector
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.