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Code result

U301A

Control Module Wake-up Circuit A/Open

Moderate severity

What it means

Open circuit on the wake-up signal line A — module cannot be woken from sleep via this path. 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.

Is it safe to drive?

Use caution

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.

Most likely causes

  • Wake-up wire broken

    high

    One of the most commonly reported causes for this code — check this first.

  • Gateway module routing CAN messages incorrectly

    low

    Less common, but worth ruling out after the more likely causes.

  • CAN terminating resistor (120 Ω) drifted out of spec

    low

    Less common, but worth ruling out after the more likely causes.

Related help

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