Honda A123 Service: What It Means
Your Honda is showing A123. Here is exactly what Honda says that code includes.
Honda A123 service: what is included
A Honda A123 code means an oil change, plus tires, air cleaner, dust and pollen filter, drive belt and transmission fluid. The Maintenance Minder builds the code from a main item (A) and sub items 1, 2 and 3. Together, the 6 services below are what Honda lists for that code.
Main item A
- Replace engine oil
Sub item 1: Tires
- Rotate tires
Sub item 2: Air cleaner, dust and pollen filter, drive belt
- Replace air cleaner element
- Replace dust and pollen filter
- Inspect drive belt
Sub item 3: Transmission fluid
- Replace transmission fluid
Notes that apply to A123
- If a Maintenance Minder message does not appear more than 12 months after the display is reset, change the engine oil every year.
- If you drive in dusty conditions, replace the air cleaner element every 15,000 miles (24,000 km).
- If you drive primarily in urban areas with high concentrations of soot in the air from industry and diesel-powered vehicles, replace the dust and pollen filter every 15,000 miles (24,000 km).
- Driving in mountainous areas at very low vehicle speeds results in higher transmission temperatures. If you regularly drive your vehicle under these conditions, have the transmission fluid changed every 25,000 miles (40,000 km).
How urgent is the A123 message
The Minder shows the code when the engine oil life reaches a threshold. Honda's message levels are:
| Message | Oil life | What it means |
|---|---|---|
| Maintenance Due Soon | 15% to 6% | The engine oil is approaching the end of its service life; the listed items should be inspected and serviced soon. |
| Maintenance Due Now | 5% to 1% | The oil has almost reached the end of its service life; service the listed items as soon as possible. |
| Maintenance Past Due | 0%, negative distance shown | The oil life has passed. A negative distance appears after driving over 10 miles (U.S. models) and blinks. The listed items must be inspected and serviced immediately. |
Other Honda codes
See every Honda Maintenance Minder code, or these related ones: A1, A2, A3, A12, A13, A23, B123.
Sources
- 2024 Honda CR-V Owner's Manual, "To Use Maintenance Minder"
- 2022 Honda Accord Owner's Guide, Maintenance Minder
- 2018 Honda CR-V Owner's Guide, Maintenance Minder
This page is a reference, not a substitute for your owner's manual. Confirm the code list for your exact model and year. Data last checked 2026-09-20.
Find your schedule
Pick your vehicle and enter your mileage. The full schedule is listed further down this page.
Frequently asked questions
What does Honda A123 service mean?
Code A123 is main item A plus sub items 1, 2 and 3. It means an oil change, together with tires, air cleaner, dust and pollen filter, drive belt and transmission fluid.
Does Honda A123 include an oil change?
Yes. Main item A is "replace engine oil". It does not include the oil filter or the inspection list, which come with main item B.
How urgent is a A123 code?
Honda's guide describes three levels. Due Soon appears at 15% oil life, Due Now at 5% to 1%, and Past Due once the car has been driven more than 10 miles beyond zero. At Past Due, Honda says the items must be inspected and serviced immediately.
Is A123 the same on every Honda?
The code letters and digits are the same system, but the sub item list differs a little between models and years. For example, sub item 6 (rear differential fluid) appears in the 2024 CR-V guide but not in the 2022 Accord guide. Check your own model's guide.
Where does this information come from?
From Honda's own Owner's Manual and Owner's Guide pages for the Maintenance Minder, linked at the bottom of this page.