Ignition

P0320 — Ignition/Distributor Engine Speed Input Circuit Malfunction

Severity: medium Drive with care, to a shop

What P0320 means

The engine control unit constantly reads engine speed from the crankshaft position sensor or a pickup in the distributor. It uses this signal to time the spark and fuel injection. P0320 sets when that signal is missing, erratic or implausible, often due to a bad sensor or damaged wiring.

Symptoms

  • Check Engine light is on
  • Engine hesitates, stumbles or misfires
  • Engine cranks but won't start
  • Reduced power and sluggish acceleration
  • Random stalling
  • Erratic RPM or a tachometer that jumps or reads zero

Possible causes

  1. Failed crankshaft position sensor
  2. Damaged, corroded or loose wiring and connectors in the sensor circuit
  3. Faulty camshaft position sensor or distributor pickup
  4. Open or short in the sensor power or ground circuit
  5. Failed ignition module
  6. Worn or corroded distributor cap and rotor (older vehicles)
  7. Internal ECM/PCM fault (rare)

How to diagnose

  1. Scan for codes and freeze-frame data, and look for related crank or cam sensor codes
  2. Check whether the scan tool shows RPM while cranking and whether the tach moves
  3. Inspect the crankshaft sensor, connector and harness for breaks, chafing, oil and corrosion
  4. Check the sensor air gap and mounting, and inspect the reluctor wheel teeth
  5. Test power, ground and signal at the sensor connector with a multimeter, using the wiring diagram
  6. Check the sensor's resistance (inductive type) or view its waveform on a scope
  7. Check the camshaft sensor and, if equipped, the distributor cap, rotor and pickup coil
  8. Suspect the ignition module and ECM only after everything else checks out

Common fixes

  • Replace the crankshaft position sensor
  • Repair or replace damaged wiring and connectors
  • Replace the camshaft sensor or distributor pickup
  • Replace the ignition module, cap and rotor if worn
  • Repair, replace or reflash the ECM/PCM if all else is good

Questions and answers

Can I drive with a P0320 code?

It's not recommended. The engine may stall suddenly and refuse to restart, which is dangerous in traffic. A short, careful trip to a shop is usually possible if the engine is running smoothly.

What most often causes P0320?

The crankshaft position sensor or its wiring and connector are the most common culprits. Start by inspecting the connector and harness, then test the sensor itself.

Why does my engine crank but not start with P0320?

Without an engine speed signal, the computer doesn't know the crankshaft position, so it won't deliver spark or fuel. The cause is usually the sensor, its circuit or the reluctor wheel.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.