What Does U0017 Mean?
The CAN Low (negative) wire voltage on the medium-speed network is higher than specification. This typically indicates a short to voltage or a problem with the CAN High circuit affecting the differential voltage.
Safety Warning
Loss of network communication can disable safety-critical systems including braking assist, stability control, and collision avoidance features. Vehicle should not be driven until repaired.
Common Causes
35%
CAN Low wire shorted to power source or CAN High wire
30%
Damaged module with internal short between CAN circuits
20%
Wire chafing causing intermittent short to voltage supply wire
10%
Corrosion or water damage creating unintended voltage path
5%
Incorrect repair or crossed wires from previous work
Diagnostic Steps
1
Step 1: Measure voltage on CAN Low circuit with ignition on and compare to specification (typically 2.0-2.5V at rest)
2
Step 2: Disconnect modules systematically while monitoring CAN Low voltage to identify source of high voltage
3
Step 3: Check for continuity between CAN Low and any power supply circuits with all modules disconnected
4
Step 4: Inspect wiring harness for damage, especially where harness passes through body panels or near heat sources
5
Step 5: Use oscilloscope to analyze CAN bus signal integrity and identify abnormal voltage patterns
Estimated Repair Cost
$200 - $2,000
Parts + labor, varies by vehicle and location
The CAN Low (negative) wire voltage on the medium-speed network is higher than specification. This typically indicates a short to voltage or a problem with the CAN High circuit affecting the differential voltage.
The most common cause of U0017 (Medium Speed CAN Communication Bus (-) High) is: CAN Low wire shorted to power source or CAN High wire
Typical repair costs for U0017 range from $200 to $2,000, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Loss of network communication can disable safety-critical systems including braking assist, stability control, and collision avoidance features. Vehicle should not be driven until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U0017 to identify the root cause.
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Quick Info
Category
Network
System
Network Communication System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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