See also:

CHECK ENGINE Malfunction indicatorlight
On-Board Diagnostics II (OBDII): As you drive, a computer called "OBDII" monitors your vehicle's engine, transmission, electrical and emission systems. The CHECK ENGINE light will light ...

Removing the cover to access the bulbs
NOTE Before starting to replace a bulb, see page 322. 1. Open the retaining clamps by pressing them to the sides. 2. Pull the cover straight out. Reinstall the cover in the reverse order. ...

Deposit control gasoline (detergent additives)
Volvo recommends the use of detergent gasoline to control engine deposits. Detergent gasoline is effective in keeping injectors and intake valves clean. Consistent use of deposit control gasol ...