Code P0321, Ignition Control 24X Signal Circuit Error: Notes

The 24X Crankshaft Position (CKP) sensor is used to improve idle spark control at low speeds. The 24X CKP is located behind harmonic balancer on front of engine and picks up pulses from reluctor wheel on crankshaft. 24X CKP signal is conditioned by PCM and used to more accurately control spark at lower engine speeds (less than 1200 RPM) where spark control is critical for idle quality.

Code P0321 will set when following conditions are present.

150 or more 3X reference pulses seen without a 24X signal pulse received.
Engine speed is less than 1200 RPM.
Engine running.

PCM will disregard 24X sensor input and base timing from 3X low resolution CKP sensor. Code P0321 does not illuminate Malfunction Indicator Light (MIL).

NOTE: Test numbers refer to numbers on diagnostic chart.

24X signal RPM should be same as engine speed up to about 1200 RPM at which time it stops. This test determines if PCM is putting out a 24X signal.
This test determines if signal voltage is present up to PCM.
This test determines if 12 volts is present at sensor input.
Pigtail and sensor integrity can be determined by applying 12 volts to 24X CKP sensor pigtail circuit.