DTC P0340: Camshaft Position Sensor - Circuit Malfunction: Reference
WARNING: This page is about a different car, the 2002 Suzuki Esteem. However, it is still accessible from the selected car via links, so may be relevant.
Backprobing at ECM, connect oscilloscope between ECM connector C20 terminal No. 2 (Black/White wire) and ECM connector C21 terminal No. 1 (Black wire). See Figure
. Compare CPM sensor waveform, to waveform in illustration. See Fig 1
.
Courtesy of SUZUKI OF AMERICA CORP.