Powertrain, generic · Ignition system or misfire

P0392 Camshaft Position Sensor B Circuit Low Bank 2

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Camshaft position sensor B is the exhaust camshaft sensor; bank 2 is the side without cylinder 1, so the code only occurs on V and boxer engines with one exhaust cam sensor per bank. P0392 means the bank 2 exhaust cam signal stays low without edges – typically a short to ground of the signal wire, a sensor output stuck low or a missing 5 V reference. Only manufacturers with separate low and high codes use it: on the Saab 9-4X 2.8 turbo V6 (GM LAU) the signal must stay low without pulses for more than 1 s, or 10 s cumulatively, after more than 10 crank revolutions and below 2,520 rpm, after two trips; GM's 2004/2005 3.6-litre V6 (LY7, LP1) counts the fault over two drive cycles. Newer GM petrol engines (2015–2020) and Ford report the same fault as P0390. The consequence is as for P0390: cam timing on bank 2 in its base position, loss of power, longer cranking.

Likely causes

Signal wire shorted to ground
Sensor faulty internally (output stuck low)
5 V reference missing (shorted by another sensor on the same circuit)
Engine module

Symptoms

  • Check engine light on
  • Loss of power (bank 2 exhaust cam timing in its base position)
  • Longer cranking
  • Rough idle

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–300
Time0.5–2 h

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

Parts involved

camshaft position sensor exhaustcamshaft tone wheelsensor wiringengine control module

Related codes

P0390P0391P0393P0394P0367P0347

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