Exhaust Variable Valve Timing CVVT Solenoid, T5 - P1 S40 V50 C30 C70 P3 S60 V60 XC60 XC70

Modern overhead cam cars like Volvo's "whiteblock" five cylinders often use variable valve timing (VVT) to make airflow in to and out of the cylinders as efficient as possible. The ends of the camshafts sit in hollow chambers inside the timing belt-driven cam gears, and these VVT cam solenoids vary oil pressure between the chambers to press on the ends of the camshaft and advance or retard/delay the camshaft timing relative to the cam gear.

If you're seeing exhaust cam timing error codes but your timing belt marks still look good, it's possible your VVT solenoids are no longer up to this oil proportioning job any more. These solenoids sit on top of the cylinder head under the engine cover, so they're cheap and easy to replace.