Here is a safer way to reset the Check Engine Light on your 2006 Volvo XC90:
• Turn on the ignition switch to position II.
• Quickly press and release the trip odometer reset button three times within five seconds.
• Turn the ignition key to the off position.
• Wait for 30 seconds.
• Turn the key to position II.
• The check engine light should be off.
• If the light is still on, repeat steps 1-5.
• If the light is still on after the second attempt, you will need to take your vehicle to a mechanic to have the code diagnosed.