P0320 on Ford: How to Diagnose & Fix
Ignition/Distributor Engine Speed Input Circuit Malfunction
1 Ford model · 1 documented issue · 1 critical · $40-$350 repair
P0320 on Ford by model: symptoms, diagnosis and fix
The distributor-mounted Thick Film Ignition (TFI) module is a chronic weak point on these Broncos. Because the module is bolted to the distributor and baked by engine heat, its internal electronics break down over time, causing the engine to miss, stumble, and stall once fully warmed up, then restart fine after cooling for 20-30 minutes. The module tends to fail once its temperature exceeds ~257F. This exact defect was the subject of a class-action lawsuit (Howard v. Ford) that Ford settled, covering an estimated 22 million Ford vehicles built 1983-1995. It is one of the single most common driveability complaints on the platform.
Common Symptoms
- Engine misses/stumbles once fully warmed up
- Stalls when hot, then restarts after cooling 20-30 minutes
- Intermittent no-start when hot
- Runs fine cold, problem returns as it heats up
How to Fix
Replace the TFI module (a common wear item). The enthusiast-preferred permanent fix is to relocate the module off the distributor onto a remote finned heat sink on the fender/firewall with an extension harness so it no longer heat-soaks. Use a quality Motorcraft module rather than the cheapest aftermarket unit, which often fails again quickly.
Sources for this issue (1)
P0320 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0320 mean on a Ford?
P0320 stands for "Ignition/Distributor Engine Speed Input Circuit Malfunction." The ECM/PCM detected a malfunction in the ignition or distributor engine-speed (RPM) input circuit. This circuit supplies the engine-speed reference used for spark timing and fuel control; a general fault here (open, short, or signal loss) is flagged as P0320. On distributorless systems this maps to the crank/ignition RPM reference. On Ford it is documented across 1 model: Bronco.
What are the most common causes of P0320?
The most common causes of P0320 are: Faulty crankshaft/distributor RPM pickup sensor, Damaged wiring or connector in the RPM input circuit, Poor ground or corroded connector, Faulty ignition module, Air gap or damaged reluctor/trigger wheel. The specific cause varies by vehicle.
How much does it cost to fix P0320 on a Ford?
Published repair estimates on Ford range from $40 to $350 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.