P0320 Code: Ignition/Distributor Engine Speed Input Circuit
The computer lost the engine speed (rpm) signal. The engine can stall suddenly or refuse to start.
Unverified: this manufacturer-specific definition comes from a single source or varies by model. Confirm it with a brand-specific scan tool.
Stop driving
Avoid highways and heavy traffic until it's fixed. If the rpm signal drops out while driving, the engine shuts off, and you lose power steering assist and most brake assist within a few pedal presses. If the engine has already stalled once, have the car towed or drive only short, slow local trips to a shop.
At a glance
Severity: High
- Meaning
- Ignition/Distributor Engine Speed Input Circuit
- System
- Ignition & Misfire · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $80–$700
- DIY difficulty
- Moderate
The engine computer needs a steady engine speed signal to know when to fire each spark plug and injector. On older engines that signal comes from a pickup inside the distributor or from the ignition module; on many later Fords and some Asian makes, P0320 is used for the crankshaft position signal as the computer receives it. P0320 means that input has gone missing or dropped out while the engine was turning. Exactly which sensor and circuit the code covers varies by manufacturer, so check service information for your engine. The typical story is a car that dies without warning once hot, the tachometer needle falling to zero just before, and then cranking without starting until it cools down.
How to read P0320
- P Powertrain
- 0 Generic (SAE)
- 3 Ignition / misfire
- 20 Specific fault
Symptoms
- Engine stalls suddenly, often once fully warm or after a long drive
- Tachometer drops to zero just before or while the engine dies
- Cranks but won't start when hot, then starts again after cooling for 20 to 30 minutes
- Intermittent stumble or cut-out on bumps
- No spark and no injector pulse during cranking
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Crankshaft position sensor or distributor pickup failing internally, typically when hot
- Damaged, oil-soaked or loose connector or wiring between the sensor and the computer
- Distributor problems: oil leaking past the shaft seal into the housing, worn shaft bushings or a failed ignition module
- Damaged or loose trigger wheel (reluctor) on the crankshaft or in the distributor
- Poor engine ground or low system voltage weakening the signal
- Faulty splice from an aftermarket remote starter, alarm or tachometer tapped into the rpm wire
- Engine computer input failure
Diagnosis step by step
Watch rpm on a scan tool while cranking
If the scan tool shows 0 rpm while the engine is clearly turning over, the computer isn't receiving the speed signal. If rpm reads normally during a no-start, the problem is elsewhere, usually fuel or ignition output.
Tools: OBD-II scanner
Identify the signal source for your engine
Check service information to see whether P0320 on your vehicle refers to a distributor pickup, an ignition module output or the crankshaft sensor. Many later Fords report a lost crankshaft sensor signal this way. This tells you which component and wires to test.
Tools: Flashlight
Test the sensor signal
A two-wire magnetic sensor should produce an AC voltage that rises with cranking speed, typically well over 0.2 volts AC while cranking. A three-wire Hall-effect sensor needs a supply voltage (5 or 12 volts) and a solid ground, and its signal wire should switch between near 0 volts and the reference as the engine turns.
Tools: Multimeter
Reproduce the heat failure
Heat-related failures often only show when hot. With the engine hot and stalled, check whether the signal is missing, or warm the sensor gently with a heat gun on low while watching rpm. A sensor that drops out when warm and recovers when cooled with a damp cloth is confirmed faulty.
Tools: Multimeter, OBD-II scanner
Inspect distributor and wiring
On distributor engines, remove the cap and check for oil inside the housing, side play in the shaft and a cracked pickup. Follow the harness for rubbed-through insulation near exhaust parts and look for add-on splices in the rpm wire.
Tools: Flashlight, Screwdriver
Where the parts are
- 1Ignition coil
- 2Spark plug
- 3Fuel injector
- 4Camshaft sensor
- 5Crankshaft sensor
- 6Engine computer (ECM)
- 7Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Replace crankshaft position sensor | Yes | $120–$350 |
| Repair sensor connector or wiring | No | $100–$350 |
| Replace distributor assembly or pickup | No | $250–$700 |
| Replace ignition control module (older engines) | Yes | $120–$400 |
| Remove faulty aftermarket splice and restore original wiring | No | $80–$250 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Ford
On many Ford vehicles P0320 is how the computer reports a lost crankshaft position signal. The crankshaft sensor itself and its connector near the front of the engine are the first things to check, especially if the engine stalls when hot and restarts after cooling.
Field data
| Ford | 2 | Explorer, Focus |
|---|
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
A stored P0320 with the check-engine light on fails an OBD emissions test. The bigger concern is safety: a car that can stall at speed should be repaired before it goes back on the highway.
Frequently asked questions
How is P0320 different from P0335?
P0335 specifically points at crankshaft position sensor circuit A. P0320 covers the engine speed input in general, which on older engines is in the distributor and on some later ones is the crankshaft signal as the computer receives it. Which one your car uses depends on the manufacturer.
Why does my car restart after it cools down?
Failing magnetic and Hall-effect sensors often develop an internal break that opens when hot and closes again as they cool. That's why the stall-then-restart pattern is so typical for this code.
Is it safe to keep driving with P0320?
Not in traffic or at speed. If the signal drops out, the engine stops and you lose power steering and brake assist. Short, slow trips to a repair shop are the most you should do.
Can a remote starter cause P0320?
Yes. Many remote starters and some aftermarket gauges tap into the rpm signal. A poor splice or a failing module can load down or interrupt the signal. Disconnect the add-on and see whether the problem stops.
Sources
- SAE J2012 – Diagnostic Trouble Code Definitions
- ISO 15031-6 – Road vehicles, diagnostic trouble code definitions (EOBD)
- Manufacturer public service information (cross-checked)
- NHTSA Complaints API
- Methodology: How We Build Code Pages · Data Sources We Use · Editorial Policy