P2511

What it means

The sense (feedback) line that lets the ECM verify the main power relay has actually closed shows intermittent dropouts. The ECM expects to see battery voltage on this line whenever the relay is energised — short losses suggest aged contacts, vibration or chafed wiring.

Is it safe to drive?

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

• Aged main relay contacts

  high

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

• Chafed sense wire shorting intermittently

  medium

  A plausible cause — test and verify before replacing parts.

• Connector with intermittent contact under vibration

  low

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

Related help

• Full P2511 diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?