Crankshaft Position Sensor
WARNING: This page is about a different car, the 2003 GMC Savana and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
The PCM uses the Crankshaft Position (CKP) sensor to detect crankshaft speed and position. The CKP sensor is located behind the harmonic balancer. See Fig 1 . The CKP sensor connects to the PCM through the 12-volt reference circuit, the low reference circuit and CKP sensor 1 signal circuit. If PCM detects that the CKP sensor signal is incorrect for 3 seconds, a DTC will set. To diagnose DTC, see SELF-DIAGNOSTICS - 4.3L CHEVY EXPRESS & SAVANA article.