Powertrain, generic · Ignition system or misfire

P0393 Camshaft Position Sensor B Circuit High 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. P0393 means the bank 2 exhaust cam signal stays high without edges. Because the engine module pulls the Hall sensor's signal line up, an open wire leads to 'high' just like a short to positive – GM's 2004 3.6-litre V6 (LY7) therefore calls the fault 'circuit continuity or high' and counts it over two drive cycles. On the Saab 9-4X 2.8 turbo V6 (GM LAU) the signal must stay high without pulses for more than 1 s, or 10 s cumulatively, after two trips. Only manufacturers with separate low and high codes use it; newer GM petrol engines and Ford report the 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 open or connector off
Sensor ground open
Signal wire shorted to positive
Sensor faulty

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

P0390P0391P0392P0394P0368P0348

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