Tohatsu outboard fault codes (or DTC codes) are diagnostic codes that apply to given malfunctions. These codes can be pulled in many different ways including using diagnostic software or decoding the flashing pattern of the three warning lights.
If you want to find out more about the topic and read the official Tohatsu 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 Tohatsu Outboard?
Just like many vehicles or heavy machinery, most Tohatsu outboards also feature an onboard computer (ECU), which is considered the ‘brain’ of the engine.
In case of a malfunction, this computer generates a code that describes a particular malfunction.
Tohatsu outboard fault codes are known by many names including service codes, error codes, and diagnostic trouble codes (DTCs).
How do You Read Fault Codes on a Tohatsu Outboard?
In a nutshell, the three easiest ways to read the fault codes on a Tohatsu outboard are as follows:
- Self-diagnostic function
- Diagnostic scanner tool
- Take the motor to a dealer or service shop
Let’s take a close look at each!
1. Self-Diagnostic Function
Many outboard motors have a built-in self-diagnostic system, and Tohatsus are no exception.
This feature is designed to detect malfunction(s) of the motor and uses three indicator LED lights to display the error code.
Also known as “warning lights,” these three LED indicator lights include the oil warning light, the engine coolant light, and the battery voltage lamp.
They are mounted on the tachometer and originally intended to display the malfunctions with the oil level, cooling water temperature, and battery, respectively.
But in case of an electric malfunction, the self-diagnosis system uses combinations of these three lamps and the tachometer indication to “blink” the error code.
These flashing patterns indicate specific malfunctions, which can be decoded by the Tohatsu fault code list (a.k.a. “Warning Indications List”) included in this post below.
The flashing warning lights are often accompanied by a specific beeping sound.
The buzzer can be built into the switch panel or the remote control box depending on the design of the motor.
This built-in warning buzzer uses one of the following operation patterns:
- Beep: Two seconds
- Beep: 0.3 second
- Beep, Beep, Beep: Three times in every two minutes
- Continuous sounding
Running the Self-Diagnostic on a Tohatsu
The self-diagnosis function on a Tohatsu is only enabled when its engine is stopped.
The process can also be stopped at any time during the procedure by turning the key switch to “OFF.”
As a rule of thumb, the self-diagnosis function of Tohatsu outboards consists of four modes, which are as follows:
- Mode 1: Tachometer operation test
- Mode 2: Display of engine operation hours
- Mode 3: Display of fault location and fault history
- Mode 4: Deletion of fault history
Let’s get down to the nitty-gritty and see how to go through each mode.
You can run the self-diagnostic procedure on a Tohatsu outboard by following these steps:
- After attaching stop switch lock, set the key switch to “ON”.
- For confirmation of meter operation, three warning lamps go on and buzzer sounds. At the same time, the fuel feed pump (FFP) operates for approximately two seconds.
- ECU attempts to identify the existence of a trouble or abnormality of a part if any.
- If there exists any trouble or abnormality, the warning buzzer lamps and buzzer operate according to the type of the trouble. (→Refer to Warning Indications List)
Go into the process of the self-diagnosis operation from here
- Set the key to “ON”, and push it in (for approximately 5 seconds) until the buzzer sounds.
- Self-Diagnosis Mode 1 [Tachometer Operation Test] After the pointer returns to “zero”, the process goes to mode 2 automatically
- Self-Diagnosis Mode 2 [Indication of engine operation hours] A combination of tachometer indication and three warning lamps represents engine operation hours. (→ Refer to Operating Hours Indication List)
- Set the key to “ON“, and push it in (for approximately 1 second) until the buzzer sounds to proceed to mode 3.
- Self-Diagnisos Mode 3 [Indication of fault location(s) and fault history] After the buzzer “Beeps” once, a combination of tachometer indication and three warning lamps represents the first fault location and fault history.→ Take action(s) by referring to the fault indication list.
- Then, every time the key switch is pushed in at “ON” position for approximately 1 second until the buzzer sound, the next fault location, and the fault history are represented. When all the fault locations are represented by going through the above operations, a state of no indication occurs. Then, when the key switch is pressed, the representation of the fault locations starts again from the first one. No indications are represented when there is no fault history (Tachometer and warning lamps do not operate.)
- Self-Diagnosis Mode 4 [Deletion of fault history] In any of the states in the self-diagnosis mode 3, the fault history is deleted by removing the stop switch lock plate and pushing in the key for approximately 3 seconds. At this moment, the buzzer “Beeps” three times. (Note: The operating hours are not deleted.)
- Set the key switch to “OFF”. The self-diagnostic function ends. Attach the stop switch to the lock plate.
- Regular Operation is resumed. The warning lamps and buzzer operate if any fault or abnormality is left unsolved. (→Refer to Warning Indications List)
Note: The self-diagnosis function is stopped at any moment during the above procedure when the key switch is set to “OFF”.
Tohatsu Fault Code List (Warning Indications List)
For your convenience, we’ve compiled the official Tohatsu Fault Code List (a.k.a. Warning Indications List) into this post.
With the help of this list, you can decode the flashing patterns of the warning lights, which will help you start troubleshooting the issue.
Without further ado, the Tohatsu fault code list is as follows:
| Buzzer | Oil warning light | Engine coolant light | Battery voltage lamp | ESG system | Error description | Reference | Solution |
| Continuous sound | – | – | – | High speed | Engine overspeeding | Approximately 6000 rpm | Adjust the propeller, the engine installation height and the trim again |
| Intermittent sound (3 short of 0.3 seconds every 2 minutes) | Flashing | – | – | – | Low oil level | Approximately 1.4L or less | Top up engine oil |
| Continuous sound | – | Flashing | – | Low speed | High coolant temperature | Approximately 85°C (varies depending on engine speed) | Consult the workshop manual |
| Continuous sound | – | Flashing | – | Forced idle | Coolant temperature too high (fault) | Approximately 90°C (varies depending on engine speed) | Consult the workshop manual |
| Continuous sound | – | Flashing | – | – | Air compressor coolant temperature high | Approximately 90°C | Consult the workshop manual |
| Continuous sound | – | Flashing | – | Low speed | Air compressor coolant temperature high (fault) | Approximately 95°C | Consult the workshop manual |
| – | – | – | Flashing | Low speed | Battery voltage too low (fault) | Around 9V or less | Consult the workshop manual |
| – | – | – | Flashing | – | Low battery voltage | Around 10V or less | Consult the workshop manual |
| – | Flashing | Flashing | Flashing | Low speed | High battery voltage | Around 18V or more | Consult the workshop manual |
| – | Flashing | Flashing | Flashing | Engine stop | Battery voltage too high (fault) | Around 20V or more | Consult the workshop manual |
| – | Flashing | Flashing | Flashing | – | Throttle valve position sensor: Incorrect idle position | Refer to the technical sheet “THROTTLE VALVE POSITION SENSOR RESET” | |
| – | Flashing | Flashing | Flashing | Forced idle | Throttle valve position sensor error | Throttle valve position sensor 1 and 2 | Check for any wiring faults. If no problems are found, replace the component |
| – | Flashing | Flashing | Flashing | Low speed | Throttle valve position sensor error | Throttle valve position sensor 1 and 2 | Check for any wiring faults. If no problems are found, replace the component |
| – | Flashing | Flashing | Flashing | Forced idle | Throttle valve position sensor supply voltage error | Throttle valve position sensor 1 and 2 | Check for any wiring faults. If no problems are found, replace the component |
| – | Flashing | Flashing | Flashing | Low speed | Throttle valve position sensor supply voltage error | Throttle valve position sensor 1 and 2 | Check for any wiring faults. If no problems are found, replace the component |
| – | Flashing | Flashing | Flashing | – | Air injector error | Check for any wiring faults. If no problems are found, replace the component | |
| – | Flashing | Flashing | Flashing | – | Fuel injector error | Check for any wiring faults. If no problems are found, replace the component | |
| – | Flashing | Flashing | Flashing | – | Ignition coil error | Check for any wiring faults. If no problems are found, replace the component | |
| – | Flashing | Flashing | Flashing | – | Fuel pump error | Check for any wiring faults. If no problems are found, replace the component | |
| – | Flashing | Flashing | Flashing | – | Crankshaft position sensor error | Check for any wiring faults. If no problems are found, replace the component | |
| – | Flashing | Flashing | Flashing | – | Defect status coolant temperature sensor | Engine or air | Check for any wiring faults. If no problems are found, replace the component |
| – | Flashing | Flashing | Flashing | – | MAP sensor error | Compressor | Check for any wiring faults. If no problems are found, replace the component |
| – | Flashing | Flashing | Flashing | – | MAP sensor error | Check for any wiring faults. If no problems are found, replace the component | |
| – | Flashing | Flashing | Flashing | – | Main power relay error | Check for any wiring faults. If no problems are found, replace the component | |
| Intermittent sound (3 short of 0.3 seconds every 2 minutes) | Flashing | Flashing | Flashing | Forced idle | Oil pump error | Check for any wiring faults. If no problems are found, replace the component |
Disclaimer: This list is for informational purposes only and is not necessarily applicable to any model. For more information, please check your motor’s service manual.
2. Tohatsu Diagnostic Software
Due to their simplicity, the warning lights can provide very limited information about the malfunction.
If you want to dig deeper and find out more about the issue, you will need a diagnostic tool. These tools are also often referred to as Toahtsu diagnostic scanners or Tohatsu DTC code readers.
One of the most well-known diagnostic tools for Tohatsu outboards is the TEXA IDC5 Marine Diagnostic Scanner Tool.
Other than Tohatsu, this tool is also compatible with many other boat motor brands including Mariner, Mercury, Honda, and more.
Note that this kit doesn’t come standard with the necessary diagnostic interface cable. This is no surprise since different motors (even within a given brand) feature different diagnostic ports.
This means that the cable that is compatible with your motor must be purchased separately.
This diagnostic tool can be used for various purposes, including:
- Reading and resetting the fault code(s).
- Reading the EMM module identification.
- Reading sensors and actuators in real time.
- Testing sensors and actuators in real time.
- Setting engine operating parameters.
- Performing engine maintenance.
- Printing engine reports.
- And more.
3. Take Your Motor to a Professional
If you can’t pull the error codes on your Tohatsu outboard motor for some reason, your last option is to take it to a Tohatsu dealer or a service shop.
Although this involves some hassle, a professional can not only pull the error codes for you but can also help with repairs.
Tohatsu Oil Light Issues
What is the Red Light on a Tohatsu Outboard?
Except for the smallest models, each 4-stroke Tohatsu outboard is equipped with an Engine Oil Warning Lamp.
If the oil quantity and pressure are sufficient in the engine, this small red warning lamp is off.
But if the light is flashing or stays on, it’s a sign that the oil pressure or the oil level in the motor is low.
If this happens, you should turn off the engine immediately and check the oil level.
How to Reset the Oil Light on a Tohatsu Outboard?
Tohatsu outboards feature a system to remind you of oil changes, which come due every 100 hours.
This is indicated via the Oil Warning Light, which blinks a short flash every 9 seconds.
Are you wondering how to reset the oil light on your Tohatsu outboard?
In a nutshell, the steps of the reset procedure are as follows:
- Connect the safety lanyard and turn the key to the “ON” position.
- After the beeping sound, pull the safety lanyard off within 1 second.
- Within 5-10 seconds, pull the red knob of the safety switch and release it within 0.5 seconds.
- Within 5-10 seconds, pull the red knob of the safety switch again and release it within 0.5 seconds.
- Within 5-10 seconds you will hear 3 beeps from the buzzer. This sound informs you that the system has reset successfully.
- Turn the key to the “OFF” position and replace the safety lanyard.
Note that this oil change reminder will make a comeback after 100 hours from the last reset.
Takeaways
Tohatsu outboard diagnostic codes are also known as fault codes, error codes, or just DTC codes.
These codes refer to given malfunctions that can be decoded by the official Tohatsu outboard DTC code list (included above).
Tohatsu outboard DTC codes can be pulled in many ways, including decoding the three warning lights or using a TEXA IDC5 diagnostic tool.
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