OBD2 code U0008: High Speed CAN Communication Bus (-) High
The CAN-Low signal is held above its valid range, typically because of a short to battery voltage on the CAN-L wire.
Detected Root Component
Network Component
Observed 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
Possible Causes
- CAN-Low shorted to battery voltage
- Chafed harness against power wire
- Gateway module routing CAN messages incorrectly
Tools Required
Interactive Diagnostic
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Parts likely to be the cause (Moteur (général))
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Frequently asked questions about code U0008
What does code U0008 mean? ▾
OBD2 code U0008: High Speed CAN Communication Bus (-) High. The CAN-Low signal is held above its valid range, typically because of a short to battery voltage on the CAN-L wire.
What are the symptoms of code U0008? ▾
Code U0008 may cause: 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. The intensity of these symptoms varies depending on the vehicle and driving conditions.
What causes code U0008? ▾
The most common causes of code U0008 are: CAN-Low shorted to battery voltage, Chafed harness against power wire, Gateway module routing CAN messages incorrectly. A proper OBD2 diagnostic will pinpoint the exact cause.
Is it serious to drive with code U0008? ▾
Yes, code U0008 is critical (Critical). Avoid driving and consult a professional promptly to prevent major damage.
How do I fix code U0008? ▾
Start by reading the code with an OBD2 scanner, then follow the interactive decision tree on this page. Priority causes to check: CAN-Low shorted to battery voltage, Chafed harness against power wire, Gateway module routing CAN messages incorrectly. Difficulty: Medium · Estimated time: 30-60min.