Honda Maintenance Minder codes explained: A, B and 1 to 7
Updated 13 October 2026 · CarsPlusBikes
Most Honda cars sold in the United States do not have a fixed service schedule printed as a mileage table. Instead, the car tells you when it needs service. The Maintenance Minder watches how the car is driven, works out how much life is left in the engine oil, and when service is due it shows a short code such as A1 or B124 on the instrument cluster. Once you know how to read the code, you know exactly what the visit should include.
How the Minder decides when service is due
The system calculates remaining engine oil life as a percentage, based on engine operating conditions such as engine speed, temperature and how long the car runs. Two identical cars can therefore reach a service at very different mileages: one used for long highway trips may go much further than one used for short trips in cold weather.
- 15% oil life: "Maintenance due soon". Book an appointment.
- 5% oil life: "Maintenance due now".
- Below 0%: a negative distance is shown, meaning the service is overdue.
After the work is done, the Minder must be reset. If it is not reset, the next reminder will be wrong.
The main codes: A and B
Every service starts with one of two letters:
| Code | What it means |
|---|---|
| A | Replace the engine oil. |
| B | Replace the engine oil and the oil filter, and carry out a set of inspections: front and rear brakes; tie rod ends, steering gearbox and boots; suspension components; driveshaft boots; brake hoses and lines (including ABS and stability-control lines); all fluid levels and condition; the exhaust system; and fuel lines and connections. |
B is therefore the bigger of the two visits. On many models the Minder alternates between A and B, but the order depends on driving, not on a fixed pattern.
The sub-codes: 1 to 7
Numbers shown next to the letter are extra jobs to do at the same visit. Not every model uses every number.
| Sub-code | Extra work |
|---|---|
| 1 | Rotate the tires. |
| 2 | Replace the engine air filter and the dust and pollen (cabin) filter, and inspect the drive belt. |
| 3 | Replace the transmission fluid (and the transfer fluid on some all-wheel-drive models). |
| 4 | Replace the spark plugs; on some engines also inspect valve clearance. |
| 5 | Replace the engine coolant. |
| 6 | Replace the rear differential fluid. All-wheel-drive models only. |
| 7 | Replace the brake fluid. |
Reading combined codes
Put the letter and the numbers together and you have the full job list:
- A1: oil change and tire rotation. The most common small service.
- B12: oil and filter change, full inspection, tire rotation, new air and cabin filters, drive belt check.
- B13: as B plus a tire rotation and new transmission fluid.
- A137: oil change, tire rotation, transmission fluid and brake fluid. Short on inspections but heavy on fluids.
- B1234567 never appears in practice on most models, because some sub-codes do not exist for them; code 6, for example, only exists on all-wheel-drive models.
If you are unsure, our Honda maintenance page has a decoder: tap the A, B and number keys in the order shown on your dash, or type the code, and it lists every job, model by model.
Time limits still apply
The Minder is based on oil life, so a car that is driven very little may not ask for service for a long time. Two time rules cover that case:
- If no Maintenance Minder message appears within 12 months of the last reset, change the engine oil anyway, once a year.
- If the message for item 7 has not appeared within 36 months of its reset, change the brake fluid every 3 years.
Severe driving and the Minder
Because the Minder measures how the car is driven, it already brings service forward for hard use such as short trips, extreme temperatures or heavy loads. Some items, however, have their own severe-use rules that the Minder does not cover, for example more frequent air filter changes on dusty roads. Our Honda page lists these rules for each model.
Common questions
Is a B service more expensive than an A service?
Yes. B adds the oil filter and a multi-point inspection, so it takes longer and costs more. The sub-codes add their own parts and labour on top.
Why doesn't my Honda show code 6?
Code 6 is the rear differential fluid, which only all-wheel-drive models have. Front-wheel-drive models such as most Civics, Accords and the Odyssey never show it.
Can I ignore the Minder and change oil every 5,000 miles?
You can change oil more often than the Minder asks, but you should not go longer. Keep receipts, use the specified oil grade and reset the Minder each time, so the reminders for the other sub-codes stay correct.
Indicative figures only, for planning and educational purposes. Exact cost and service requirements may vary with your car, its condition and your city; contact your local authorised service centre before a visit. CarsPlusBikes is independent and is not affiliated with or endorsed by any car manufacturer.