How to read diagnostic trouble codes?

We can think of today's cars just like computers. For this reason, cars can malfunction, just like computers. With today's cars, there are nearly 80 control units that regulate and manage the electronic components in the vehicle. When any malfunction occurs in the vehicle, these are stored in the form of OBD2 fault codes and you can understand the fault in your vehicle by reading these codes.

There are several ways to diagnose your vehicle. One of these is to take the vehicle to a repair garage, where the fault codes are read by the technicians. However, there is a faster and more practical option! You can read the fault codes yourself. For this, you need an OBD2 scanner and software that works compatible with this scanner.

If you have an OBDTalk device, all you have to do is plug it into the OBD2 port and open the app. After running the diagnostic feature with the phone app, you can see all the error codes.

You can also see live data and ECU information on the same screen.

First of all, by reading the fault codes, you will understand your vehicle better. We will show you what the fault codes are, how to read the fault codes and how to do them in the best way. Thanks to all this, you will become your own mechanic.

What Are Diagnostic Trouble Codes?

Sometimes problems can occur in the vehicle. Often, the control units are able to correct these faults on their own. Each fault is logged as a DTC (diagnostic trouble code).

Problems that control units cannot solve appear on the dashboard. Flashing fault lights on the dashboard may indicate a serious malfunction. In such cases, the engine must be switched off immediately to avoid further damage to the vehicle.

There are different types of error codes, and most of them have the same logic. Each digit in the error codes has different meanings. There are approximately 10000 codes and these codes are arranged according to SAE J2012 and ISO 15031-6 standards.

What does the first digit in the DTC’s mean?

The first digit in the error codes indicates the region where the error came from. The letters below indicate the regions.

• P(powertrain): engine and transmission
• C (Chassis) = Chassis
• B (Body) = Body
• U (User Network) = Network

What does the second digit in the DTC’s mean?

The second digit tells whether it is a standard code or a manufacturer specific code.

• 0 = Standard code
• 1 = Manufacturer specific code

What does the third digit in the DTC’s mean?

The third digit in the error codes indicates the subsystems associated with this code.

• 0, 1, and 2: air and fuel metering control
• 3: Ignition system
• 4: Additional emission control

What does the fourth and fifth digit in the DTC’s mean?

The fourth and fifth digits of the error codes show you the actual error. The application will show you all the error codes in detail.

Which Fault Codes Are Recorded?

Faults can occur once or multiple times in different parts of your vehicle. The control units can repair these faults themselves, if they repair themselves, the driver is not warned, the fault is stored in the memory. However, some errors cannot be repaired by the control units, manual intervention is required.

If we give an example of these faults, it may be the oil level. When the oil level drops below a certain level, the driver is warned and the error is stored in the memory. Brake fluid and wiper fluid have the same logic.

In addition, some faults are not immediately alerted to the driver, but these are more complex faults that must ultimately be dealt with. For example, serious malfunctions occur due to strong factors such as the electronic system in the vehicle, high temperature level, humidity, abrasions, and therefore, part replacements may be required.

In order to have regular information about the health status of your vehicle, you should regularly read the errors in the vehicle. With OBDTalk you can read the faults at the vehicle, without driving to a workshop first.

Once you have your own OBD2 reader, you won't have to pay the mechanics all the time.

This way you see early which system raises the warning.

What Is The Working Logic Of Electronic Control Units?

We can think of ECUs as computers with microprocessors inside. They are responsible for controlling all electronic systems in the vehicle. Via sensors, information is transmitted to the control units. The incoming value is compared. If there is a deviation, the control unit takes the necessary action.

There are different fault codes for each situation. In cases where the control unit cannot correct the fault itself, the driver is warned with warning lights. All ECUs have CAN bus, so scanners receive all data via OBD2.

What Is The OBD2 Scanner?

An OBD2 scanner gives access to the in-vehicle communication bus. OBDTalk connects your vehicle and the mobile app over Bluetooth and reads the supported ECU data.

How To Get Data From OBD2 Via An App?

Getting data with the OBDTalk app is simple: plug the device into the OBD port, open the app, connect over Bluetooth and select the vehicle and ECU.

Reading and clearing DTC is quite simple, there are 4 steps for them;

• First get the OBDTalk device.
• Then download our mobile app via App Store or Google Play.
• Connect your scanner to your car's OBD socket.
• The last step is to open the OBDTalk app and select the vehicle and ECU.

You can read and process error codes in minutes. However, in some cases it may take up to 20 minutes to read.

If you want to see the old and new data after performing a scan, you must delete the fault memory in the vehicle. You can read the data again after clearing the memory. OBDTalk reads fault codes on supported brands and ECU systems; supported models and functions are published in the support list.

Why should we read DTC’s regularly?

Reading the fault codes is important to reach the fault in advance so that there is no serious fault in the vehicle. If the error appears constantly, there is probably an error in the system.

Faults occurring in the vehicle are interrelated. For example, if there is a fault in the Lambda sensor (the sensor responsible for measuring the correct ratio of combustion air to fuel), this can subsequently lead to higher fuel consumption and higher emissions. If you get a lambda related fault, you will also have a mass airflow sensor fault. In this case we can assume that the lambda sensor is working fine, but there may also be a leak in the corrosion. Repairing this leak is less costly than replacing the lambda sensor.

How to delete DTC?

You can read fault codes, correct and delete faults.

Since faults can usually be deleted by themselves, you can delete them without fixing them. Many faults are periodically cleared from the ECU memory. However, in some cases it is not automatically deleted. In this case, it is necessary to delete it manually. If an error you deleted before reappears later on, the situation may be serious, in these cases it is necessary to examine the malfunction in more detail.

Engine errors should be dealt with immediately, but media errors will not affect the vehicle much, so they will not affect the vehicle in a short time.

Can The Service Light Be Deleted Using An OBD2 Scanner?

When it's time for oil maintenance, the vehicle is warned with a service reminder, which is quite tedious. It is not stored in vehicle memory and therefore is not read during diagnostics

However, by using the service function of OBDTalk, you can perform service resets and see the maintenance data recorded in your vehicle. In this way, you can do the maintenance yourself, saving time and money.

The use of this feature varies from vehicle to vehicle. First of all, you need to check if this feature is compatible with your vehicle.

Read Heavy Vehicle Fault Codes with OBDTalk

OBDTalk is a Bluetooth device that plugs into the vehicle's OBD2 port plus a phone app. It connects to ECU systems verified on the vehicle itself on DAF, Ford Trucks, Mercedes-Benz and Renault Trucks heavy vehicles: 9 models, 61 ECUs. No computer or extra hardware is required.

What you can do at the vehicle:

• Read fault codes and clear the supported ones.
• Watch live data: engine speed, temperature, pressure, AdBlue dosing and more.
• See ECU name, software version, calibration and hardware number.
• Get AI-assisted explanations for supported faults.
• Run injector coding and oil service reset on the Ford Cargo MD1CE100.
• Collect the readings in a single report.

Seeing which system the fault belongs to before driving to a workshop saves time and money for fleet maintenance teams, mobile service teams, roadside assistance crews and heavy vehicle technicians. Supported models, ECUs and functions vary by vehicle version.