WRENCHIFYDecode another
Code result

U3509

Control Module Input Power C Circuit Low

High severity

What it means

Input power line C 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.

Is it safe to drive?

No — stop driving

This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.

Most likely causes

  • Weak battery or high supply resistance

    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

Get the full diagnosis

Add your vehicle and see step-by-step repair help, recalls, and TSBs in Wrenchify.

Diagnose U3509 free

No credit card required