P25A9

What it means

The piston-cooling oil-jet control circuit is open. Modern engines with under-piston oil jets switch them on under high load to cool the piston crown — controlled by a solenoid valve in the oil gallery. With the circuit broken, jets cannot be commanded on or stay locked off, raising piston temperatures under load.

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

• Open control wire to the solenoid

  high

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

• Open solenoid coil

  medium

  A plausible cause — test and verify before replacing parts.

• Pin pushed back out of connector body

  low

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

Related help

• Full P25A9 diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?