U0036
Generic (SAE) Basic entry
Vehicle Communication Bus A (shorted to Bus A)
Severity
Medium
Typical repair cost
50 – 700 EUR
System
Network
What it means
U0036 indicates a fault on the vehicle communication bus itself rather than in one component: Vehicle Communication Bus A (shorted to Bus A). Several modules may log related codes at the same time.
Advertisement728 × 90
Symptoms
- Several warning lights on at the same time
- Functions controlled by the affected module do not work
- Scan tool cannot communicate with one module
- Gauges dropping to zero or dashboard flickering
Common causes
- Blown fuse or no power supply to the Vehicle Communication Bus A (shorted to Bus A)
- Poor ground for the module
- Damaged CAN/data bus wiring or connector
- Failed module
- Low battery voltage during cranking or after a jump start
How to diagnose
- Check which modules respond to a full system scan and which do not
- Verify fuses, power and ground at the Vehicle Communication Bus A (shorted to Bus A) connector
- Measure CAN bus resistance between the two bus wires (about 60 ohms with the battery disconnected) and inspect the wiring
- Check battery voltage and charging system; low voltage causes many communication codes
- Replace or reprogram the module only after power, ground and bus wiring are confirmed
Frequently asked questions
Can I keep driving with U0036?
Usually yes for a short time, but expect reduced performance or higher fuel use. Have it diagnosed within a few days.
Will clearing U0036 fix it?
No. Clearing only erases the stored code; it returns as soon as the monitor runs again unless the cause is repaired.
Related codes
Nearby codes in this group
- U0035Vehicle Communication Bus A (High)
- U0037Vehicle Communication Bus B
- U0034Vehicle Communication Bus A (Low)
- U0038Vehicle Communication Bus B (Performance)
- U0033Vehicle Communication Bus A (Open)
- U0039Vehicle Communication Bus B (Open)
- U0032Vehicle Communication Bus A (High)
- U0040Vehicle Communication Bus B (Low)