P0320 critical

Ignition/Distributor Engine Speed Input Circuit Malfunction

The P0320 code means the vehicle's onboard diagnostic system has detected: Ignition/Distributor Engine Speed Input Circuit Malfunction. This is a critical severity code.

My Garage →

Keep driving?: No -- stop driving
DIY difficulty: moderate
Estimated cost: $100 - $400 (parts and labor)

Recommended Tool

ANCEL AD310 OBD-II Scanner

Best-selling code reader on Amazon. Reads and clears check engine codes on any 1996+ vehicle. Under $30.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Every Tech Needs This

AstroAI Digital Multimeter

Essential for diagnosing sensor codes, checking voltage, and testing circuits. Under $15 and pays for itself on the first job.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Common Symptoms

Engine will not start or cranks but fails to fire
Engine stalls suddenly while driving
Tachometer reads zero or fluctuates erratically
Check Engine Light illuminated
Intermittent loss of power

Probable Causes (Ranked by Likelihood)

Faulty crankshaft position sensor or distributor pickup Very High
Damaged or corroded sensor wiring or connector High
Cracked or missing reluctor ring teeth Moderate
Excessive sensor air gap Moderate
PCM/ECM engine speed input circuit failure Low

Step-by-Step Diagnostic Procedure

Check for crankshaft position sensor (CKP) signal using a scan tool -- RPM should read during cranking
Test CKP sensor resistance -- typical range is 200-2000 ohms depending on sensor type
Inspect the CKP sensor connector for corrosion, oil contamination, or damaged pins
Check the reluctor ring (tone ring) on the crankshaft for damaged or missing teeth
Verify the sensor air gap is within specification -- typically 0.5-1.5mm

Frequently Asked Questions

Can I drive with code P0320?

No. Without a reliable engine speed signal, the PCM cannot control ignition timing or fuel injection. The engine may stall without warning or refuse to start.

What is the difference between P0320 and P0335?

P0320 is used primarily by Chrysler/Dodge/Jeep and refers to the ignition/distributor speed input. P0335 is the generic code for crankshaft position sensor circuit malfunction. Both indicate similar problems.

Can a bad crankshaft sensor cause a no-start?

Yes. The crankshaft position sensor is essential for the PCM to determine engine position and control spark and fuel delivery. Without this signal, the engine cannot start.