P0320=Ignition Engine Speed (Profile Ignition Pickup (PIP)) input circuit malfunction.
The following is from the Ford TSP (Technical Service Publication):
NC1 CONTINUOUS MEMORY DTC P0320: ERRATIC IGNITION
Continuous Memory Diagnostic Trouble Code (DTC) P0320 indicates two successive erratic Profile Ignition Pickup (PIP) pulses occurred resulting in a possible engine miss or stall.
Possible causes:
-- Loose wires/connectors.
-- Arcing secondary ignition components (coil, wires, plugs, etc.).
-- On-board transmitter (2-way radio).*
Are any of the above present?
*Verify all 2-way radio installations. Carefully follow manufacturer's installation instructions regarding the routing of antenna and power leads.
Yes
SERVICE as necessary. Complete PCM Reset to clear DTCs (REFER to Section 2A, «Powertrain Control Module (PCM) Reset»). RERUN «Quick Test».
No
For No Starts:
GO to Pinpoint Test Step «A1».
For Intermittent Faults:
GO to Pinpoint Test Step «Z50».
All others:
Loss of PIP. REPLACE PCM.
A simple test to check for arcing, is to take your car to a VERY dark spot at night, pop the hood, and watch the engine.
