P0321

DTC P0321 Ignition Control 24X Signal Diagnostic Chart:

Ignition Control 24X Signal Wiring Schematic:

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

DIAGNOSTIC TROUBLE CODE (DTC) P0321 WILL SET WHEN
^ Engine is running.
^ Engine RPM below 1200 RPM.

ACTION TAKEN (PCM WILL DEFAULT TO)
Four spark reference (24X) pulses to be seen between two fuel control (3X) pulses. If the sequence of these pulses is not correct for 50 engine revolutions, DTC P0321 will set. Once DTC P0321 is set, it latches and the PCM will ignore the 24X pulses (if it reappears) for the remainder of the ignition cycle. DTC P0321 does illuminate the MIL (Service Engine Soon).

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test determines if signal voltage is present up to the PCM.
2. This will determine if 12 volts is present at the sensor input.
3. By applying 12 volts to the 24X crankshaft sensor pigtail circuit, pigtail and sensor integrity can be determined.
4. Ground path continuity is determined with this test.

DIAGNOSTIC AIDS
An intermittent 24X signal error can be caused by poor connections. Ignition feed, reference low and the signal circuits should all be checked for poor connections.