U0058: Vehicle Communication Bus D (+) Low

What it means

Bus D high-side line voltage below expected range. A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.

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 D carries data between the modules connected to that network. The control module sets U0058 when the positive (high-side) bus D line is below its expected electrical range, which can disrupt messages on that bus.

Common causes

Most likely first.

1. Wire shorted to ground
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 first, noting whether the low-line fault appeared with communication loss or other bus D codes.
2. Identify which bus D modules are not responding and check whether the problem is shared across the network.
3. Inspect the bus D positive wire and connectors for a short to ground, pin damage, moisture, or chafing against the body.
4. With power isolated according to the manufacturer's procedure, test the positive conductor for an unintended ground connection and check continuity through the affected sections.
5. Check bus D termination and gateway routing against the manufacturer's diagnostic procedure after the wiring checks.

Common fixes

• Repair insulation damage where the bus D positive line is shorted to ground.
• Clean or repair a damaged connector or terminal pulling the positive line low.
• Correct a bus D termination fault if measurements fall outside the manufacturer's specification.
• Repair or replace the gateway only if tests confirm incorrect routing is causing the low-line condition.

Can I keep driving?

Limit driving if warnings or functions are affected, because communication loss can disable dependent features or put a module into limp mode. Stop if an essential system is impaired; continued use can leave you without functions that rely on bus D data.