OBD2 code U0009: High Speed CAN Communication Bus (-) Shorted to Bus (+)
CAN-High and CAN-Low are shorted together.
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-H and CAN-L shorted together
- Pinched harness behind a module
- 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 U0009
What does code U0009 mean? ▾
OBD2 code U0009: High Speed CAN Communication Bus (-) Shorted to Bus (+). CAN-High and CAN-Low are shorted together.
What are the symptoms of code U0009? ▾
Code U0009 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 U0009? ▾
The most common causes of code U0009 are: CAN-H and CAN-L shorted together, Pinched harness behind a module, Gateway module routing CAN messages incorrectly. A proper OBD2 diagnostic will pinpoint the exact cause.
Is it serious to drive with code U0009? ▾
Yes, code U0009 is critical (Critical). Avoid driving and consult a professional promptly to prevent major damage.
How do I fix code U0009? ▾
Start by reading the code with an OBD2 scanner, then follow the interactive decision tree on this page. Priority causes to check: CAN-H and CAN-L shorted together, Pinched harness behind a module, Gateway module routing CAN messages incorrectly. Difficulty: Medium · Estimated time: 30-60min.