U0033

What it means

The communication bus A low-side line (CAN-L) is open — broken wire, unplugged connector, or terminator missing.

Is it safe to drive?

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

Most likely causes

• CAN-L wire broken or unplugged

  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

• Full U0033 diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?