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.
- Keep driving?
- No — stop driving
- DIY difficulty
- moderate
- Estimated cost
- $100 - $400 (parts and labor)
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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
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.
Mechanics Guide Step-by-step diagnosis
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
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
Commonly Affected Vehicles
- 2003-2013 Dodge Ram 1500
- 2004-2014 Jeep Grand Cherokee
- 2005-2015 Chrysler 300
- 2006-2016 Dodge Charger
- 2007-2017 Jeep Wrangler
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