How To Read Obd2 Codes Without Scanner Gm

Author: | Update On: May 9, 2021
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OBD2 trouble codes are part of the vehicle troubleshooting systems. With that, you can trace your engine’s problem. When the scanner finds an issue during operation it will isolate the issue and translate it into a code. it just saves the codes for your access to help you to understand the problem for the car maintenance.

OBD 2 scanners use the sensor to attach to the car’s OBD2 port. It diagnoses the vehicles for troubles and helps to read the codes but how to read obd2 codes without scanner gm? You can use the ignition method and odometer process to read the obd2 codes without a scanning tool.

What Are Obd2 Codes?

On-Board Diagnostic (OBD) is a self-diagnostic system that is common in all kinds of vehicles. Vehicles are equipped with a computer and Power Control  Module that operates a regular check to make sure the vehicles are in a good condition. When it diagnoses and finds a problem, it generates DTC Codes ( Diagnostic Trouble Codes) then turns on the check engine light. That means the car has some malfunction and needs maintenance.

Why We Need to Read Obd2 Codes Without Scanner

All the car mechanics regularly use scanning tools like CRP909E Full System OBD2 Scanner. As obd 2 trouble codes help to find the issue and repair on time. On the other hand, not all the drivers use the scanning devices or if they do it might stop working in the middle of a go.

read obd2 codes without scanner gm

Don’t worry if it stopped working or if you don’t have it. If you know the tactics to read the obd2 codes without a scanner with some tips there is nothing to fear. It is money-saving as you won’t have to buy the scanner and more efficiently. Because of that, it is important to know the methods of reading obd2 codes without a scanner.

Why Does Your Mini Check Engine Light On?

The mini check engine light is part of the OBD system on a Mini Cooper. It is the most dreaded onboard warning for most drivers. It is impossible to read the mini cooper engine trouble code without a scanning tool. Most scanning tools display the trouble code with a one-line description.

There are reasons to cause the mini check engine lights on, a loose or broken gas cap, fouled spark plug wires, faulty oxygen sensor, and more. However, this is the only obd system that you cannot diagnose without a scanner.

How to Read Obd2 Codes Without Scanner Gm?

The process is very simple to unblock the OBD 2 codes without a scanner. Just you need to know the serial codes. Just follow my instructions to learn the tactics on How to Read Obd2 Codes Without Scanner Gm?

how to read obd2 codes without scanner gm

Method: Ignition Key

Retrieving the OBD 2 codes with the help of ignition keys is a simple process. Using the process you can check engine codes. Here are the steps:

Ignition Key

Step 1: Use the Ignition Key

use the ignition key to switch on / off the lock key without cranking the engine. It depends on the vehicle how many times you need to do the process. Some vehicles need only three rounds and some of them need a five-round maximum. Just finish the process by keeping the key in the ON position.

Step 2: Watch the Dashboard

while doing the first step, be careful about the crank otherwise you have to start it again. During the process keep an eye on the dashboard for the check engine light.

Step 3: Check Engine Lights

In this step, the engine light will start to blink and flush. Simultaneous long and quick flashes will indicate the number. Generally, every pulse indicates a number, to understand the number you have to understand the signals it indicates.

The long flush represents the first number of the trouble code and the short flashes indicate the second number of the trouble code. As an example. The long pulse with a pause means the trouble code is 41.

Step 4: Write Down the Codes

If you cannot understand the codes instantly it is better to write down the flashes and try to find the exact code from the servicing book. It is the best way for beginners.

Method: Odometer


Step 1:  check the ports

Try to find the diagnostic test link, the port where scan devices are plugged in. usually, it is located under the dashboard near the driver’s seat. If there are 12 ports instead of 16, just connect ports A and B with a paper clip or jumper wire. Keep watching the check engine light as documented above for the Ignition method

Step2: Start the Engine

keep the car key in the ON position during depressing the odometer continuously and use the Trip and Reset buttons if you have the digital dash cluster. In this method, the odometer displays the trouble codes so that you can read them.

Step 3: Repeat the Process

Do the Trip and Reset process by turning the car on/off several times. While the engine key is on, finish the process then release the odometer buttons.  release the odometer buttons. The odometer countdown the codes and display them in certain models.

Following these ways, you can read the obd2 codes without a scanner. In the beginning, it might be tough and takes a long time to find the codes and understand them. When you will use it continuously you will learn quick coding and it will be easy for you to read the obd 2 codes without the scanner.


There are many methods to read the obd2 codes without the scanner gm. Here I have explained only two easy methods. If the Ignition method doesn’t work on any specific vehicle then try using the odometer method to decode the obd2 codes.

Nowadays the scanning tools are available that scan the vehicle, displays the obd2 codes, and helps to understand them. But in case of a failure of the scanning tools how to read obd2 codes without scanner gm? I hope now you know the process to read the obd2 codes without a scanner gm.

How To Read Obd2 Codes Without Scanner Gm 1

William Hedlund

Hi, I am William Hedlund, I am a motor tool specialist and a businessman. I have a business where I sell all the latest obd2 scanners for honda & jeep, best automotive diagnostic scanner, off-road air compressor, best battery for winching, etc. Because of my business, I have to face so many clients of these tools users. While selling these products and giving them service, I saw many clients face difficulties with installation, maintenance, not getting the exact amount of service, and buying the wrong one. All those problems they face because of their lack of knowledge about these products.

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