P0390 Code: Camshaft Position Sensor “B” Circuit Bank 2

The powertrain control module (PCM) uses critical data signals from the camshaft position sensor(s) and crankshaft position sensor to determine the correct injection sequence and ignition timing. If the camshaft position sensor is unable to send a signal to the PCM, on-board diagnostics will log a P0390 code.

What Does the P0390 Code Mean?

Diagnostic trouble code (DTC) P0390 stands for “Camshaft Position Sensor ‘B’ Circuit Bank 2.”

The camshaft position sensor determines when the no. 1 cylinder has reached its top dead center (TDC) compression. Once the cylinder reaches this phase, the camshaft position sensor will generate a pulse signal that’s sent to the PCM.

A camshaft position sensor can either be a hall-effect sensor or a magnetic reluctance sensor. Either way, it reacts to the tone ring to generate a signal.

Note: The definition of code P0390 might be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Common Causes of the P0390 Code?

• Camshaft position sensor failure
• Broken tone ring
• Wiring issues
• Powertrain control module issues
• Issues with the variable valve timing system
• Problems with the timing chain and related components

What are the Common Symptoms of the P0390 Code?

• Illuminated check engine light
• No-start condition
• Decreased engine performance
• Poor fuel economy

How to Diagnose the P0390 Code

While DTC P0390 is a generic powertrain code that can be logged in vehicles with an OBD-II system, keep in mind that vehicle specifications can affect the diagnostic process. Depending on the make and model, additional steps might be needed to diagnose the trouble code.

Diagnosing this type of trouble code might require you to use a scan tool and inspect the affected system for signs of damage. If you’re not familiar with the process of diagnosing trouble codes, it’s best to have a certified mechanic do the job for you instead. Otherwise, you can go ahead and do it yourself.

To help you out, here’s a video that shows what the process might involve.

How to Fix the P0390 Code

Attempting to fix a DTC P0390 can be frustrating and confusing if you don’t have the right tools and technical knowledge. If done incorrectly, it might even lead to further complications and heftier repair costs. Under these circumstances, it’s best to leave the job to a certified professional to ensure all the steps and protocols are followed correctly.

But if you know your way around resolving trouble codes, then you’re well aware that there’s no magic bullet that will fix all DTCs for all makes and models. So if you want to resolve the issue on your own, make sure you have the right repair information before you begin. Guides like those from Chilton or an ALLDATA subscription contain vehicle-specific repair information, which will come in handy when working on your daily driver.