U1448 Vauxhall Viscount is defined as Camshaft Position Sensor A Circuit Low. This means the CMP (camshaft position) sensor circuit on engine bank 1 sends an irregular reading. The PCM then uses this data to provide the right strategies for the fuel delivery and ignition timing of the engine.
Possible Causes :
If you find a related TSB, the information will often help in diagnosing the code in question as TSBs are crested from many thousands of repairs. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground.
Diagnostic trouble code U1448 Vauxhall Viscount is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.
Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before U1448 Vauxhall Viscount.
Fortunately, U1448 Vauxhall Viscount is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.