P0320: Ignition/Distributor Engine Speed Input Circuit Malfunction
6 vehicles · 3 makes · $30-$550 repair
Most Reported On
P0320 is an OBD-II diagnostic trouble code meaning “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. This code is most commonly reported on 1999-2004 Jeep Grand Cherokee, 1994-2001 Ram 1500, and 1990-1999 Jeep Cherokee (SE, Sport, Classic, Country, Limited), plus 3 other vehicles, with repair costs ranging from $30 to $550.
Common Causes
Typical Repair Cost
Based on 6 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0320, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (6)
1999-2004 4.7L P0320 or Crank-No-Start — Test the CKP Signal and Circuit First
Crankshaft Position Sensor (CPS) Failure Causes Intermittent No-Start and Hot Stalling
4.0L Crankshaft Position Sensor Thermal Failure — Random Stalling & Hot No-Start
FAQ
What does P0320 mean?
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.
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?
Repair costs for P0320 range from $30 to $550, depending on the vehicle and root cause.
Which vehicles are affected by P0320?
Au7o has documented P0320 across 6 vehicle models from 3 manufacturers: Jeep, Mazda, Ram.
Sources (12)
- Manual2004 Jeep Grand Cherokee 4.7L Service Manual: P0320 Diagnostic
- Manual2004 Jeep Grand Cherokee 4.7L Service Manual: CKP Sensor Service
- RecallNHTSA 04V-112: 2004 Grand Cherokee 4.0L CKP Recall Population
- articleCam Sensor Failure Causing No Start or Stalling: Dodge Ram 1500 - RepairPal
- ForumI solved my camshaft sensor issue - RamForumZ
- ForumNo Start Troubleshooting (Cam and Crank Sensors) - Jeep Cherokee Forum
- ForumCrank but no start when hot - NAXJA Forums
- articleJeep Cherokee XJ - Crankshaft Position Sensor Issue - NewParts
- ForumInternal distributor oil leak, leaking into cap - Mazda MX-6 Forum
- ForumMazda 626 Stalling/Starting Issues Due to Distributor Failure
- ForumOil Leak / distributor - Mazda626.net V6 forum
- ForumNo Start After Distributor Cap Replacement on Mazda Protege (RepairPal)
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.