P0393 code meaning
Camshaft Position Sensor B Circuit High Bank 2
Powertrain system Generic code P03xx codes Check engine light
What P0393 means
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 gasoline 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.
P0393 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P0393
- Check engine light on
- Loss of power (bank 2 exhaust cam timing in its base position)
- Longer cranking
- Rough idle
Common causes of P0393
- Most likelySignal wire open or connector off
- PossibleSensor ground open
- PossibleSignal wire shorted to positive
- PossibleSensor faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Camshaft position sensor exhaustCamshaft tone wheelSensor wiringEngine control module
What each part of P0393 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 3 | Area: ignition system or misfire. |
| 93 | The exact fault in that area. |
What to do next
- Note P0393 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0393
What does P0393 mean?
P0393 means "Camshaft Position Sensor B Circuit High Bank 2". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0393?
Drive gently and only to a workshop. With P0393 the car can go into limp mode (reduced power) to protect itself.
Will P0393 fail an emissions test?
Yes, it can. P0393 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0393 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0393 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.