P0651 OBD-II Trouble Code: Sensor Reference Voltage B Circuit Open

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0651 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0651 code

P0651 is a diagnostic trouble code (DTC) for "Sensor Reference Voltage B Circuit Open". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P0651 DIAGNOSTIC Get a fair and transparent estimate upfront

check engine light

P0651 code definition

The P0651 indicates that the sensor reference voltage B circuit is open. This code applies to all manufacturers.

What the P0651 code means

This generic code shows that there is some type of fault in the sensor reference voltage "B", and is detected by one of the other sensor 5 voltage circuits or the engine control module or ECM. The voltage could be higher or lower than expected.

What causes the P0651 code?

A number of different things could potentially cause the P0651 code. The common causes include:

What are the symptoms of the P0651 code?

The symptoms of a P0651 code can vary, so it is important to get an understanding of the different issues you might face. It might include a hard or no start condition, the engine could start running rough, or you might notice that the vehicle no longer has the same fuel efficiency that it once did. The engine might misfire, and you would likely notice a lack of power in the vehicle. If the trouble code is stored, and the Check Engine Light isn’t on, it might show the code as pending. However, in other cases, the engine light might be on.

How does a mechanic diagnose the P0651 code?

The Onboard Diagnostics II standardized system is a computer system in many cars and trucks today that allows the vehicle to run self-diagnostics and reports. A mechanic will utilize an OBD-II scanner to diagnose the problem with your vehicle and access data regarding the fault and necessary repair. They will examine the data to determine when a code was set, reset the codes, and then test the vehicle to determine when the code returns, if it does. In many cases, the mechanic will be able to determine the problem based on the data they receive. Determining that it is the P0651 code and not one of the other trouble codes lets them know the next actions they need to take to help get the vehicle back in shape.

Common mistakes when diagnosing the P0651 code

The biggest mistakes when dealing with the P0651 code diagnosis, or any diagnosis for that matter, is spending time looking at symptoms and stored codes that are present in the vehicle that might not have anything to do with the P0651 code. If a mechanic tries to rush through the job or skips parts of the testing process, they will not get an accurate result, and they will often misdiagnose the vehicle’s actual problems. Naturally, this will lead to repairs that do not work.

How serious is the P0651 code?

The P0651 sensor code can be a big problem for your vehicle. While it might still be possible to drive the vehicle, at least for a time, the fuel efficiency may suffer. As mentioned earlier, in some cases the vehicle will be more difficult to start, and it might not start up at all. It’s always a good idea to get any issues with your vehicle fixed as quickly as possible.

What repairs can fix the P0651 code?

The following are some of the common ways to deal with the P0651 code:

Additional comments for consideration regarding the P0651 code

Many vehicles will start to have sensor issues as they get older and have more miles put onto them, and it doesn’t always mean it is a sign to worry. Have the mechanic check with the OBD-II scanner, test the vehicle, and reset the codes. Many times, the codes will not return, and you will not need to do any repairs to the vehicle. However, if the code does come back and the issues with your vehicle continue or get worse, you will want to take it in for repair.

Need help with a P0651 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

P0651
trouble codes
Check Engine Light

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0651 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.5/5

Number of Reviews

3,696

Rating Summary
3,372
162
42
24
96
3,372
162
42
24
96

Kinder

18 years of experience
40 reviews
Kinder
18 years of experience
Kinder was on-time, polite, professional, and very competent.
2008 GMC SAVANA 3500 - CHECK ENGINE LIGHT IS ON - DOUGLASVILLE, GEORGIA

Alex

13 years of experience
405 reviews
Alex
13 years of experience
Alex arrived early and was very professional. He wont be able to work on my car, but he told me I could text him if I didn't receive contact from any other mechanics. Very impressed.
2009 ACURA TSX - CHECK ENGINE LIGHT IS ON - FRISCO, TEXAS

Joshua

13 years of experience
27 reviews
Joshua
13 years of experience
awsome and was on time
2006 SATURN ION - CHECK ENGINE LIGHT IS ON - DAYTON, OHIO

Jamahl

17 years of experience
722 reviews
Jamahl
17 years of experience
Great job and knows what he is doing. I will always refer him!
2005 TOYOTA SEQUOIA - CHECK ENGINE LIGHT IS ON - SAINT CLOUD, FLORIDA

More related articles

P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...

Related questions

Q: Q: Throttle Position Sensor

Anytime you go to a parts store to get a computer scan for the Check Engine Light you are not getting a diagnosis of the problem but only a code retrieved from the engine control module (ECM) memory. This is...

Q: Where is the circuit one camshaft position sensor located?

Hello. The camshaft position sensor is located on the passenger side of the engine bay, on the cylinder head near the coolant reservoir tank. The reservoir tank needs to be removed in order to access it. If you need help...

Q: my 2008 yukon was in two accidents in 30 min. i now have codes popping up i have had a check tire monitir system, air suspension a

It sounds as though the trouble codes are probably a result of the accidents. With no warnings prior to them, and now having them on, I can only assume that this was the cause. But, it would be necessary to...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com