Error code 48 is CAMSHAFT position sensor signal missing. Below are the instructions for replacing the sensor on a VS, not sure how different this is for a non-Ecotec VR:
REMOVE
1. Disconnect battery earth lead.
2. Lift up retaining tang and disconnect wiring harness connector from camshaft position sensor.
3. Remove camshaft position sensor to front cover retaining bolt.
4. Remove camshaft position sensor and O-ring from front cover.
REINSTALL
1. Apply light engine oil to O-ring on new camshaft position sensor.
2. Assemble camshaft position sensor into front cover hole.
3. Install camshaft position sensor to front cover retaining bolt and tighten to the correct torque specification - 11 Nm.
4. Reconnect wiring harness connector to camshaft position sensor.
5. Reconnect battery earth lead.
DTC 72 is used to detect an intermittent failure. If a hard VSS fault exists, it will set DTC 24. DTC 72 will set if the vehicle is operating at a road speed and something happens to the VSS signal.
Check all connections for proper retention. When Diagnostic Trouble Code 72 is set, the transmission will have maximum line pressure and command 3rd gear only. If DTC 72 is set while in 4th gear, the vehicle will stay in 4th gear. However, as the vehicle is coasting to stop the transmission will downshift normally from 4 to 3. Once the downshift into 3rd gear has occurred, the vehicle will stay in 3rd gear.
Check that wiring harness for VSS are not routed near high voltage sources such as spark plug cables which could induce a false signal onto the VSS signal. DTC 72 could possibly be set by rapidly accelerating the vehicle in a loose material (such as sand or gravel) where the wheels can be spinning faster than actual vehicle speed then having the spinning wheel rapidly decrease when it contacts a hard surface. This includes burnouts !!!
