Powertrain, generic · Ignition system or misfire

P0389 Crankshaft Position Sensor B Circuit Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Some engines have a second crankshaft sensor or a second track on the tone wheel – GM's 3.4/3.5/3.8-litre V6 use the low resolution track of a dual Hall sensor, the Honda 3.5-litre in the Saturn Vue Redline a second sensor – which the engine module checks against sensor A or the camshaft. By its J2012 name P0389 means the signal of sensor B drops out for moments or becomes erratic – missing or extra edges – without staying permanently low or high. Such faults are typically found by counting pulses against sensor A or the camshaft, as GM's 3.8-litre V6 and the Honda engine do; both, however, report the result under P0385/P0386, and no manufacturer document available to us uses P0389. The description therefore follows the J2012 name, these component sources and CARB. Typical causes are a loose contact, a broken wire and interference.

Likely causes

Loose contact or corrosion at the sensor B connector
Wire break or chafing that appears with engine movement
Electrical interference (add-on devices, routing near ignition or relays)
Tone wheel damaged or dirty, air gap too large
Sensor faulty, temperature-dependent

Symptoms

  • Check engine light on, possibly only after several trips
  • Occasional stalling or jerking
  • Sporadic starting problems

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–350
Time0.5–3 h

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

Parts involved

crankshaft position sensor bcrankshaft tone wheelsensor wiringengine control module

Related codes

P0385P0386P0388P0339P0335

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com.