Honda Civic: Deciphering a B12 Code - VehicleHistory (2024)

Have you been driving your Honda Civic for a few months since your last visit to your mechanic and noticed a new code light up on the dash?

The B12 is a very common maintenance code that every Honda owner will see at some point. Find out what your car wants you to do next.

What does B12 mean when it shows up on the instrument cluster in my Honda Civic?

Your car is telling you that it is time for an oil and filter change, to rotate the tires, and to change out your cabin and engine air filters. This is part of your Maintenance Minder system.

Now you are wondering how your sporty compact sedan or coupe knows that it is time for some TLC. Get all the answers with this quick FAQ on your Honda Civic Maintenance Minder system.

How Does the Maintenance Minder System Work in My Honda Civic?

The computer in your Honda Civic keeps track of how many miles you drive and how long the engine sits and idles. At the recommended maintenance intervals, the Maintenance Minder will light up an alphanumeric code in the center of your instrument cluster that indicates what kind of routine maintenance is suggested.

Once the maintenance is completed, the minder system is reset to start the countdown to your next oil change.

What Do the Different Numbers Mean in the Honda Maintenance Minder System?

All of the codes for the Maintenance Minder for your Honda Civic are included in your Owner’s Manual. If you see the letter “A,” it only needs the oil changed. The letter “B” indicates that you need the oil and filter changed. The numbers stand for a variety of other routine maintenance including:

1. Rotate tires and check pressure and wear
2. Replace air filters and check the belt
3. Transmission and transfer case fluid
4. Replace spark plugs and inspect water pump, timing belt, and valves
5. Engine coolant
6. Rear differential fluid

As such, code B12 is not B twelve, but actually B, one, and two. You can see a code combination of just the letter or a letter and one or more numbers.

How Do I Reset the Maintenance Minder in My Honda Civic?

Insert your key and turn or press the Start button to reach the ON position. Do not start the engine.

Scroll through your vehicle information pages using the Sel/Reset button until you see the Oil Life page in the center of your instrument cluster. Hold the Reset button down until the code flashes. Let go and then press and hold the Reset button again until the oil life reads 100% and the alphanumeric code clears.

What Will Happen If I Don’t Change the Oil and Rotate the Tires?

Nothing bad will happen immediately if you postpone your oil change. However, your engine needs clean new oil to continue to function.

If you never change out the oil, eventually the fluid breaks down and stops providing the protective lubrication that allows your pistons and valves to move thousands of times per minute. Tires will wear more on one side when they are not rotated, leading to premature failure.

Basically, following the maintenance schedule will help keep your car rolling while minimizing mechanical failures. Once the car determines that your oil has no viscosity remaining, a wrench will appear on your dash and remain lit until the oil is changed out.

I Never Get a Maintenance Minder Code. When Should I Get the Oil Changed?

If you only take your Honda Civic a couple miles to the store or church once a week, you may not actually reach the threshold for the Maintenance Minders to appear. However, your car should still go in for an oil change, filter replacements, and tire rotation at a minimum of once a year to keep it in prime condition.

Has All the Recommended Maintenance Been Completed on the Honda Civic You Want to Buy?

If you are checking out a pre-owned Honda Civic online or at a local dealer’s lot, make sure that the B12 was not cleared without having the proper work done. Get a complete maintenance history by visiting VehicleHistory.com and entering the VIN of the car to get a quick download.