P0393: 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. 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.

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.

Symptoms

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

Most likely causes

• Signal wire open or connector off
• Sensor ground open
• Signal wire shorted to positive
• Sensor faulty

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and look for metal filings on the sensor
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. See whether there is an RPM signal while cranking
4. Measure the signal with an oscilloscope if you can
5. Check the engine timing before replacing expensive parts

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P0393 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 3: Ignition and misfires
• 93: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0393?

Avoid driving: the engine can stall while moving. If the timing is off, continuing can cause serious damage.

What causes code P0393?

The most common causes are: signal wire open or connector off; sensor ground open; signal wire shorted to positive.

Related codes

• P0390Camshaft Position Sensor B Circuit Bank 2
• P0391Camshaft Position Sensor B Circuit Range/Performance Bank 2
• P0392Camshaft Position Sensor B Circuit Low Bank 2
• P0394Camshaft Position Sensor B Circuit Intermittent Bank 2
• P0368Camshaft Position Sensor B Circuit High Bank 1
• P0348Camshaft Position Sensor A Circuit High Bank 2

Sources

• saabwisonline.com: dtc p0341 p0342 p0343 p0346 p0347 p0348 p0366 p036
• gsi.ext.gm.com: 2004file14
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.