What Does U0072 Mean?
The positive and negative wires of communication bus E are shorted together. This prevents proper differential signal transmission on the network.
Safety Warning
May cause complete loss of communication between critical safety systems. Vehicle may not start or may be unsafe to drive.
Common Causes
40%
Physical damage causing bus E+ and E- wires to contact each other
25%
Melted or corroded connector causing cross-circuit connection
20%
Water intrusion in connector creating conductive bridge between circuits
10%
Aftermarket accessory installation damaging CAN bus wiring
5%
Failed termination resistor or module causing bus voltage collapse
Diagnostic Steps
1
Step 1: Measure resistance between bus E+ and E- wires at multiple points along the harness, should read open circuit (OL)
2
Step 2: Inspect all connectors on bus E for melting, corrosion, or bent pins causing cross-connection
3
Step 3: Check for water intrusion in connectors and junction boxes along bus E circuit
4
Step 4: Trace wiring harness looking for pinch points, routing near sharp edges, or physical damage
5
Step 5: Disconnect modules sequentially to determine if short is internal to a module or in the harness
Estimated Repair Cost
$200 - $1,200
Parts + labor, varies by vehicle and location
The positive and negative wires of communication bus E are shorted together. This prevents proper differential signal transmission on the network.
The most common cause of U0072 (Vehicle Communication Bus E (-) shorted to Bus E (+)) is: Physical damage causing bus E+ and E- wires to contact each other
Typical repair costs for U0072 range from $200 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May cause complete loss of communication between critical safety systems. Vehicle may not start or may be unsafe to drive.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U0072 to identify the root cause.
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Quick Info
Category
Network
System
Network Communication
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
