Maintenance code b14, i can not find a definition in the owners manual

If a b14 code pops up on your Accord, you can fix it as follows:
1. Replace engine oil and filter
2. Check the tire pressure and rotate the tires
3. Check drive belt, install a new air cleaner element, and replace the dust and pollen filter
4. Replace the transmission fluid if required
5. Replace timing belt and spark plug if need be
6. Change the engine coolant
7. Also, replace the back differential fluid
Note: if the problem gets resolved at step 1, you don't need to move forward with the rest of the steps.

Your owner's manual will have the fluid capacity specs; or you can call a Nissan dealership local to your area to ascertain that info; even a local auto parts store can answer that too.

The B postcode area, also known as the Birmingham postcode area,[2] provides postcodes for the boroughs of Birmingham, Solihull, Sandwell and Walsall and parts of Warwickshire, Worcestershire and Staffordshire in England.

The B14 on your Honda Civic 2006 can be fixed by following these steps:
1. Replace engine oil or if need be, replace engine oil as well as the oil filter
2. Rotate the tires and check that they have the recommended pressure
3. Replace the air cleaner element, and the dust and pollen filter, also inspect if the drive belt is in perfect condition
4. Replace the transmission fluid
5. Replace the timeing belt if damaged and the spark plugs, also adjust the valves and inspect the water pump
6. Replace the coolant
7. Replace the differential fluid
Ideally, you should check the error status after each step, and stop when it goes away. However, you should ensure that all parts and fluids are as per requirement.

Major caveat to joserivera34's answer: For "B4" it depends on if the car has a belt or chain. The Accord V4 has a chain and therefore there is no timing belt replacement. The V6 has a belt.

hav it scanned at a partsplace-but dont change any item till u git a data stream run--codes are general and can be secondary to the issue

In the owners manual is a section on programming a new personal code. You cannot change the factory code without changing the BSM ( Body Security Module )

If you did not get an owners manual with your truck ( purchased used ), you can download one from Ford :
https://www.fleet.ford.com/maintenance/owners_manuals/default.asp

Maintenance Codes:

A - Replace just engine oil
B - Replace engine oil & filter

1. Rotate tires & check air pressure
2. Replace air cleaner element, check drive belt and replace dust & pollen filter
3. Replace Transmission fluid & transfer fluid (if equipped)
4. Replace spark plugs, timing belt, inspect water pump, valve adjustment
5. Replace engine coolant
6. Replace rear differential fluid

If you have a B14, it's B, 1, 4 as in the list

If you are lucky , the original owner may have written it down in the owners manual or maintenance guide.

Go to: www.ford.fleet.com
Click on 'Maintenance' and then click 'Owners Manual' fill out the make and model, it will automatically generate a list of documents. Click on the PDF doc. you are looking for, (it also gives you info on how to save from here.)
A new window will come up if you have Adobe Reader (free at abobe.com) installed on your PC, (this is where I saved the doc.from.)
This is a FREE manual!