Volvo: fault code, variable valve timing, volvo c70

Question
Hi Volvo c70 2.3t 1999 fault code ecm-644a camshaft control faulty
postion. and ecm-6440 camshaft reset valve signal to high, but
the car runs fine does any body have any ideas, if you reset ecu
the light comes back on 1to2 days later

Answer
John,
There is a fault with the Variable valve timing (VVT). The oil passages maybe clogged not allowing it to work or the solenoid has gone bad so when the control unit calls for a change nothing happens to change the timing and the light sets for a fault code. The timing belt may have been done and the VVT was not properly set before removing the belt and is now out of time. With the Volvo scan tool a test can be run to check proper operation.