U0018: Medium Speed CAN Communication Bus (-) shorted to Bus (+)
What Does U0018 Mean?
U0018 is a diagnostic trouble code indicating: Medium Speed CAN Communication Bus (-) shorted to Bus (+). This code relates to the network communication system. It has been reported in NHTSA complaints across 1 different vehicle models.
Symptoms of U0018
- ⚠️ Check engine light illuminated
- ⚠️ Engine stalling or dying
- ⚠️ Vehicle enters limp/reduced power mode
Real Owner Reports
From NHTSA complaint database — actual owner descriptions.
"While driving at approximately 60 MPH on a highway, the vehicle suddenly lost motive power, stalled, and entered "limp mode," shifting into neutral or a low gear unexpectedly. This failure caused a rapid deceleration in high-speed traffic, effectively disabling the vehicle and creating an immediate "
— Chrysler 200 owner, 12/10/2025
Source: NHTSA Complaints Database
Most Reported Vehicles for U0018
Based on NHTSA owner complaint data.
| # | Vehicle | Reports |
|---|---|---|
| 1 | CHRYSLER 200 |
Frequently Asked Questions
What causes communication codes?
Can a bad battery cause network codes?
What To Do Next
Possible Fixes
- 🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
- 🔧 Check battery voltage and ground connections; inspect CAN bus wiring
- 🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)
-
1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
-
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
-
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.