Powertrain, generic · Ignition system or misfire

P0321 Ignition/Distributor Engine Speed Input Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0321 belongs to the same signal as P0320 and P0322: the speed and reference input of the ignition, formerly the distributor's Hall pickup, today practically always the crankshaft position sensor. Range/Performance means a signal is present but implausible – wrong number of teeth between the reference gaps, erratic tooth times, or a speed that does not fit the camshaft signal. No manufacturer document available to us describes P0321 by code: Ford runs these tooth checks under P0320 or P0339 (wrong tooth count after the gap, tooth time outside 30 to 9,000 rpm, gap at the wrong position) and GM under P0336. The description therefore follows that logic and CARB's rationality requirement for crank angle sensors.

Likely causes

Crankshaft position sensor faulty or aged (weak, noisy signal)
Sensor loose or air gap wrong
Tone wheel damaged or clogged with metal chips
Interference, poor ground or damaged wiring
Engine module or software

Symptoms

  • Check engine light on
  • Jerking, misfire or brief stalling
  • Hard starting, long cranking
  • Tachometer flickers or drops out

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–350
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

crankshaft position sensorcrankshaft tone wheelsensor wiringengine control module

Related codes

P0320P0322P0323P0336P0339P0016

References: newtonnet.co.uk, fordservicecontent.com, law.cornell.edu, hella.com.