P20D5

What it means

Exhaust Aftertreatment Fuel Injector B Stuck Open: the control module has detected this fault condition. This injector doses fuel into the exhaust to raise temperature for diesel particulate-filter regeneration; it does not fuel the engine.

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

• Injector stuck open

  high

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

• Carbon or debris buildup preventing free movement

  low

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

• Component wear with age - mechanical play

  low

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

Related help

• Full P20D5 diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?