P2771 Code: Four Wheel Drive (4WD) Low Switch Circuit

The four-wheel-drive (4WD) switch enables the vehicle to change transfer case gear ratios to two-wheel high, neutral, four-wheel high, or four-wheel low drive. This switch actuates the vehicle’s 4WD system so that it can engage in different drive modes. If the calculated transfer case gear ratio does not match the position of the transfer case switch, the transfer case control module (TCCM) and/or powertrain control module (PCM) will register a P2771 code.

What Does the P2771 Code Mean?

Diagnostic trouble code (DTC) P2771 stands for “Four Wheel Drive (4WD) Low Switch Circuit.” This generic powertrain code can apply to vehicles with 4WD or AWD.

Two-wheel-drive systems require a differential to allow the drive wheels to travel different distances and speeds while cornering or driving over bumps. Four-wheel-drive systems have a differential in the front wheels and another in the rear wheels.

The transfer case is a drivetrain component that diverts engine torque from the transmission to the front and rear differentials. It allows the vehicle to engage different gear ratios, such as low-speed, high-power. The 4WD switch is monitored by the TCCM and/or the PCM. If the calculated transfer case gear ratio does not match the position of the transfer case switch, the vehicle’s computer will log a P2771 code on a scan tool.

Note: The definition of code P2771 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 P2771 Code?

• Failed 4WD switch failure
• Internal transfer case issues
• Faulty control module or software in need of an update
• Wiring issue

What are the Common Symptoms of the P2771 Code?

• Illuminated check engine light
• Disabled 4WD
• Additional dashboard warning lights turn on

How to Diagnose the P2771 Code

You’ll have to take your vehicle’s make and model into account when diagnosing a P2771 code or any DTC for that matter. Diagnostic steps can vary depending on your vehicle’s configuration. For example, what might work to resolve a P2771 code in a Chevy Silverado might not work for a Ford F-150. That’s why it’s important to consult your vehicle’s repair manual or a reliable mechanic before diagnosing this code to avoid costly mistakes. However, if you aren’t confident in executing this step yourself, we recommend hiring a mechanic to take over your vehicle’s diagnosis and repairs. They can save you a lot of time and hassle.

How to Fix the P2771 Code

The first step to clearing a P2771 code is finding its underlying cause or causes. You’ll have to thoroughly examine your vehicle to figure out the correct fix. Fortunately, there are many OBD-II resources available online that can assist you in diagnosing and fixing your vehicle’s problems. You should look for technical service bulletins for your vehicle as your problem might have a common solution. We also suggest getting Chilton repair manuals and an ALLDATA subscription because both resources contain comprehensive factory repair information, which will be useful for DIY repairs.

Where to Get a New 4WD Switch for Your Vehicle

Avoid driving your vehicle until you have replaced its faulty 4WD switch. Otherwise, the 4WD system will remain disabled, making it much harder to drive your vehicle and increasing the risk of another part getting damaged or developing an issue. Thankfully, CarParts.com makes getting a replacement 4WD switch easy.

At CarParts.com, shopping for a new 4WD switch takes only a few clicks or taps. Simply enter your vehicle’s details, such as the year, make, model, and engine, in our website’s vehicle selector to pull up the parts that meet your applications. Our parts are ready to ship from the nearest distribution center, so your order will arrive at your doorstep in several business days. Our 4WD switches are competitively priced, so you have no need to break your budget to get your car back on the road.

So what are you waiting for? Get the best deals on 4WD switches at CarParts.com and order what you need today!