Crankshaft Position Sensor: Spectra
NOTE:
DO NOT use OBD-II Data Link Connector (OBD-II DLC) for lab scope power source, as this will affect waveform.
Backprobing connect lab scope positive probe to ECM connector B01 terminal No. 34 (White/Green wire) and negative probe to ECM connector terminal No. 78 (Black/Yellow wire A/T only) or ECM connector terminal No. 74 (Black/Yellow wire M/T only). See Figure. Start engine and allow it to reach normal operating temperature. With engine at idle, observe CKP waveform. Compare to normal waveform. See Fig 1. If CKP sensor waveform is erratic, replace CKP sensor.