What Does U0068 Mean?
The positive wire (Bus E+) voltage is measuring above specification, typically shorted to power or experiencing incorrect voltage supply. This prevents proper differential signaling and communication between modules.
Safety Warning
Overvoltage can damage multiple control modules and disable critical safety systems. Vehicle should not be driven until repaired to prevent further module damage and ensure safety system functionality.
Common Causes
40%
Short to power source in Bus E positive wiring creating overvoltage condition
30%
Failed control module with internal short to voltage supply rail
15%
Incorrect repair or wiring modification routing power to Bus E+ circuit
10%
Damaged wiring touching power wire or fuse box connections
5%
Aftermarket accessory installation with incorrect wire tap into Bus E+ line
Diagnostic Steps
1
Step 1: Measure voltage on Bus E positive line with ignition on (normal is 2.5V, high would be near battery voltage)
2
Step 2: Disconnect modules sequentially while monitoring voltage to identify module with internal short to power
3
Step 3: Check for resistance between Bus E positive wire and battery voltage with all modules disconnected
4
Step 4: Inspect recent repairs or aftermarket installations that may have incorrectly tapped into Bus E wiring
5
Step 5: Isolate and repair short to power, then verify Bus E+ voltage returns to proper specification
Estimated Repair Cost
$120 - $1,200
Parts + labor, varies by vehicle and location
The positive wire (Bus E+) voltage is measuring above specification, typically shorted to power or experiencing incorrect voltage supply. This prevents proper differential signaling and communication between modules.
The most common cause of U0068 (Vehicle Communication Bus E (+) High) is: Short to power source in Bus E positive wiring creating overvoltage condition
Typical repair costs for U0068 range from $120 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Overvoltage can damage multiple control modules and disable critical safety systems. Vehicle should not be driven until repaired to prevent further module damage and ensure safety system functionality.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U0068 to identify the root cause.
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Quick Info
Category
Network
System
Vehicle Communication Network
Difficulty
Type
Generic (SAE)
Recommended Tools
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