Powertrain, generic · Ignition system or misfire

P0385 Crankshaft Position Sensor B Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Some engines have a second crankshaft sensor or a second track on the tone wheel, which the engine module checks against sensor A or the camshaft. P0385 means its signal is missing or does not match. GM's 2004 Northstar 4.6 V8 counts the crank pulses per cam pulse (target 48 ± 1, fault in 8 of 10 tests) and also flags 2 s while cranking or 0.4 s running without a match, after two trips; an active P0385 suspends the cam sensor check. GM's 3.8-litre V6 (2006) sets it when its low resolution track stays silent while the medium resolution track delivers 36 pulses, 40 of 50 samples. The Honda 3.5-litre in the 2004 Saturn Vue Redline sets it when the second crank signal is missing while the first runs, judged after 17 revolutions, in the first trip. The engine usually keeps running on sensor A.

Likely causes

Crankshaft position sensor B faulty
Connector or wiring open or corroded
Tone wheel or second track damaged
Engine module

Symptoms

  • Check engine light on
  • Longer cranking
  • Tachometer flickers, rough running
  • Rarely stalling

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 sensor bcrankshaft tone wheelsensor wiringengine control module

Related codes

P0386P0387P0335P0336P0341

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