U0064: Vehicle Communication Bus E

What it means

A fault is detected on vehicle communication bus E. The code identifies the bus but does not specify the cause.

At a glance

• Usually lights the warning light of the system that lost communication
• The engine or gearbox may go into limp mode

How it works

Vehicle communication bus E is a network that exchanges data among the modules assigned to it. U0064 reports a fault on bus E but does not specify a particular wire condition, so the control module detects a communication or network problem without identifying its source.

Common causes

Most likely first.

1. Wiring or node fault on bus E
2. Gateway module routing CAN messages incorrectly
3. CAN terminating resistor (120 Ω) drifted out of spec

Symptoms

• Multiple warning lights may illuminate
• Affected modules may go into limp mode or shut down
• Specific functions inoperative depending on module
• Diagnostic tools may show communication faults

How to diagnose it

1. Record all module codes and freeze-frame details, noting whether the reports point to bus E or to a broader vehicle power or network issue.
2. Check which bus E modules respond and which do not, using the vehicle's network layout to identify affected nodes.
3. Inspect accessible bus E wiring, connectors, and splices for looseness, corrosion, chafing, or damage.
4. Check the bus E conductors and termination using the manufacturer's diagnostic procedure, since this code does not identify an open or short by itself.
5. Verify gateway routing only after the bus E wiring, node connections, and termination have been checked.

Common fixes

• Repair damaged or loose wiring or connectors on bus E.
• Clean or replace corroded terminals at an affected bus E node.
• Correct bus E termination if it does not meet the manufacturer's specification.
• Repair or replace the gateway only if testing confirms that bus E messages are being routed incorrectly.

Can I keep driving?

If bus E linked features are unavailable or warning lights appear, restrict driving to what is necessary because affected modules may lose data or shut down. Stop if an essential vehicle function is impaired.