Honda outboard fault codes are diagnostic codes that apply to given malfunctions. These codes can be pulled in many different ways including decoding the blinking pattern of the check engine (MIL) light or using diagnostic software.
If you want to find out more about the topic and read the official Honda outboard fault codes in one list, this post is for you.
We at PowerSportsGuide have compiled all you need to know under one roof!
What are Fault Codes on a Honda Outboard?
Just like any street vehicle, most Honda outboards also feature an onboard computer, which is considered the ‘brain’ of the motor.
In case of a malfunction, this computer (a.k.a. Engine Control Module or ECM) generates a code that describes a particular malfunction.
Honda outboard fault codes are known by many names including error codes, service codes, and diagnostic trouble codes (DTCs).
How do You Read Fault Codes on a Honda Outboard?
Simply put, the four ways to diagnose and pull the fault codes on a Honda outboard are as follows:
- HondaLink Marine
- Check engine light (MIL)
- Honda YDS Marine Diagnostic tool
- Take the motor to a Honda dealer
Let’s take a close look at each!
1. HondaLink Marine
The latest Honda outboards come with HondaLink Marine connectivity. This remote monitoring system is designed to monitor and report on your Honda outboard in real time.
The system includes a user-friendly smartphone app combined with onboard hardware and optional sensors.
If any malfunction occurs, it will more than likely be indicated in this mobile application.
But if you have a Honda outboard that lacks HondaLink Marine connectivity don’t worry, as there are many other ways to diagnose your motor.
Let’s go ahead and discuss your other options!
2. Check Engine Light (MIL)
Most Honda outboards come with an onboard diagnostic tool that can describe a malfunction via an error code. How?
Simply put, by blinking the check engine light. This means the check engine light of Honda outboards is actually a malfunction indicator lamp (MIL).
In case of a malfunction, this lamp starts to blink and its flashing pattern refers to a specific error code.
Where can you find the check engine light?
If the boat features an ignition key switch panel the check engine light is typically planted into this panel. Other models feature a small display on the throttle control unit.
In contrast, on larger tiller Honda outboards you can find this small display mounted on top of the tiller. (Unfortunately, portable Honda outboards lack any displays or diagnostic devices.)
The check engine light is the red light right next to the engine symbol.
If a malfunction occurs, the self-diagnostic system of the ECM turns the check engine light ON.
To learn more about the nature of the malfunction, you have to pull the present error code(s).
How do you do this?
As a first step, you have to short-circuit the red service check connector when the check engine light is on.
Just remove the engine cover and locate the 4P (red) service check connector located inside the electric parts cover.
The next step is to attach an SCS service connector (part number 070PZ-ZY30100) to this connector. Alternatively, you can shunt the wires with a small cable or a paper clip, as shown in this tutorial:
(Just make sure to shunt the right cables. If you have doubts, invest in a twist-proof SCS service connector, which cannot be incorrectly connected.)
Once the connector or shunt cable is connected observe the check engine light.
It should be blinking, indicating the possible malfunction by the length and the number of blinks.
When multiple malfunctions occur simultaneously, the check engine light indicates them by blinking the various error codes, one after another.
Now check the numbers and the length of the blinks. The number of long blinks indicates the first digit while the short blinks indicate the second digit of the error code.
Some examples:
- One short blink: DTC 1
- Three short blinks: DTC 3
- One long and four short blinks: DTC 14
- Two long and two short blinks: DTC 22
Once you’ve pulled the code, you can easily identify the problem with this Honda outboard DTC list:
Honda Outboard Fault Code List
No. of blinks of MIL | Probable problem part |
MIL does not come ON or does not blink. | Open circuit in MIL wire Blown MIL bulb Open circuit in ECM ground wire Faulty ECM |
MIL stays ON | Short circuit in service check connector wire Short circuit in MIL wire Short circuit in power supply line for ECM Faulty ECM |
1 | Disconnected oxygen sensor connector Short or open circuit in oxygen sensor wire Faulty oxygen sensor Spark plug misfire |
3 | Disconnected MAP sensor connector Short or open circuit in MAP sensor wire Faulty MAP sensor |
4 | Disconnected CKP sensor connector Short or open circuit in CKP sensor wire Faulty CKP sensor |
6 | Disconnected ECT sensor connector Short or open circuit in ECT sensor wire Faulty ECT sensor |
7 | Disconnected TP sensor connector Short or open circuit in TP sensor wire Faulty TP sensor |
8 | Disconnected TDC sensor 1 connector Short or open circuit in TDC sensor 1 wire Faulty TDC sensor 1 |
10 | Disconnected IAT sensor connector Short or open circuit in IAT sensor wire Faulty IAT sensor |
13 | Disconnected BARO sensor connector Short or open circuit in BARO sensor wire Faulty BARO sensor |
14 | Disconnected IAC valve connector Short or open circuit in IAC valve wire Faulty IAC valve |
21 (BF225A) | Disconnected VTEC solenoid valve connector Short or open circuit in VTEC solenoid valve wire Faulty VTEC solenoid valve |
23 | Disconnected knock sensor connector Short or open circuit in knock sensor wire Faulty knock sensor |
24 | Disconnected overheat sensor 1 connector Short or open circuit in overheat sensor 1 wire Faulty overheat sensor 1 |
25 | Disconnected overheat sensor 2 connector Short or open circuit in overheat sensor 2 wire Faulty overheat sensor 2 |
26 | Disconnected oil pressure switch (high pressure side) connector Short or open circuit in oil pressure switch (high pressure side)wire Faulty oil pressure switch (high pressure side) |
41 | Disconnected oxygen sensor heater circuit connector Short or open circuit in oxygen sensor heater circuit wire Faulty oxygen sensor heater circuit Spark plug misfire |
58 | Disconnected TDC sensor 2 connector Short or open circuit in TDC sensor 2 wire Faulty TDC sensor 2 |
7,13 | Open circuit in sensor output voltage line (brown/white) |
1,6,13,7,10,24,25 | Open circuit in sensor ground line (green/red) |
Disclaimer: This chart is for informational purposes only! For more information, please check the official service manual.
For a better understanding, we’ve represented some codes visually:


3. “Dr. H” Honda Diagnostic Tool
If you want to find out more about the nature of the malfunction, you will need a diagnostic tool like the Dr. H Honda diagnostic scanner.
This tool contains computer software and a special diagnostic cable.
The software has to be installed on your laptop while the diagnostic cable is intended to connect the laptop to the diagnostic port.
This user-friendly tool can provide detailed engine reports, not just a single DTC code!
To be more precise, the list of the functions of this diagnostic tool is as follows:
- DTC – This is the DTC (Diagnostic Trouble code) mode contained in the ECU.
- All DTC History – Displays data when the DTC contained in the ECU appears.
- Data list – Displays sensor, actuator, ECU internal data in real time.
- Graph mode – A function for making line graphs.
- Snapshot – Possible to record the existent values for items on the data list.
- Simple diagnosis – A mode that enables a simple diagnosis.
- Function test – Automatically runs each device to enable its condition to be tested.
What’s more, the Dr. H diagnostic tool can be used to pull the full history of the entire operating time, including:
- Number of starts
- Max RPM hours of operation (split between partial use and total time)
- Details of any warnings that might have been triggered during operation (such as overheating, over-revving, fuel flow, oil pressure, etc.)
Drawbacks?
Mainly its price that varies between $400 and $600 depending on the retailer.
4. Take Your Boat to a Dealer
If you can’t pull the diagnostic code on your Honda outboard for any reason, your last option is to take it to an authorized Honda dealer or a professional service shop.
Although this involves some hassle and expense, a shop can not only read the code for you but can also help with repairs.
How do You Reset the Maintenance Light on a Honda Outboard?
According to service manuals, you can reset the maintenance light on a Honda outboard by resetting the ECM. The exact steps of this process are as follows:
ECM reset procedure:
Perform the following steps 4 through 6 within 20 seconds to reset the ECM.
1. Turn the ignition switch OFF.
2. Short-circuit the 4P service check connector (red) located inside the electric parts cover using the special tool (SCS connector).
3. Turn the ignition switch ON.
4. With the lanyard clip engaged in the emergency stop switch, press the emergency stop switch for 0.5 seconds or more, then release the switch for 0.1 seconds or more. Repeat this procedure 5 times.
Proceed immediately to steps 5 and 6. Steps 4 through 6 must be performed within 20 seconds.
5. Be sure that the buzzer sounds twice.
The MIL should stay ON.
6. Turn the ignition switch OFF. (ECM reset procedure completes.)
Why is Your Honda Outboard Motor Beeping?
When you turn on the engine key on a Hodna outboard, all the indicator lights come on for a short time, and you can also hear the buzzer sounds twice.
If the buzzer sounds continue, it indicates an issue that has to be fixed. The most common reasons why a Honda outboard is beeping are as follows:
- Low oil level
- Overheating
- Charging system malfunction
- Engine control system malfunction
Takeaways – FAQs About Honda Outboard DTC Codes
Honda outboard diagnostic codes are also known as error codes, fault codes, or just DTC codes.
On most fuel-injected Honda outboards you can pull the DTC code through the check engine light. Also known as a malfunction indicator light (MIL), this device is designed to indicate fault codes by blinking different patterns.
To pull the present codes all you need to do is short-circuit the red 4P service connector with an SCS service connector (part number 070PZ-ZY30100) or a simple paper clip.
Once this is done, you can decode the blinking pattern with the official Honda fault code chart.
You can also monitor and troubleshoot the latest Honda outboards with the innovative HondaLink Marine app.
If you want to do a complete diagnostic you will need a Honda outboard scanner like the Dr. H diagnostic tool.
As a last word, if you can’t pull the code, you can still take the motor to an authorized Honda dealer or a shop.
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