Reading the codes in a GM is possible without a scantool only through the 1995 model year.
If you can not read codes with a scanner you have a wiring problem.
You need a engine scanner and then go into transmission trouble codes. Write them down,get a book, look them up, and read. Most scanners will tell you whats going on.
An engine code reader tool is needed to read a vehicle's engine trouble codes. Most auto parts store have them available and they can check the code for you by plugging it into your vehicle's OBD port (found under the driver's side of the dashboard). The displayed code(s) can then be looked up on a table of descriptions or found online to tell you what is wrong with the vehicle.
Yes, an OBD-II scanner can read diagnostic trouble codes (DTCs) without the engine running, as long as the vehicle's ignition is in the "ON" position. This allows the scanner to communicate with the vehicle's onboard computer and retrieve stored codes. However, some real-time data may not be available until the engine is running.
If it is a U.S. car then it is an OBDII compliant vehicle and the codes can be read with an OBDII scan tool.
To read a check engine code a person will need a code reader. They can also take their vehicle to an Auto Zone store and have them read the codes and explain what they mean for free.
Check engine light codes, known as Diagnostic Trouble Codes (DTCs), are alphanumeric codes generated by a vehicle's onboard diagnostic system when it detects an issue. These codes can indicate a wide range of problems, from minor issues like a loose gas cap to more serious engine or emissions system failures. To read these codes, a mechanic or vehicle owner typically uses an OBD-II scanner. Understanding the specific code can help diagnose and address the underlying problem effectively.
The Service Vehicle Soon indicator is usually a light bulb, headlight, or something to do with the vehicle. The Service Engine Soon indicator is anything that could be wrong with the Engine. Some computers can read codes for either, but some computers can only read codes for the Service Engine indicator.
If there is something wrong with the engine, a person can find out by scanning it for codes. A scanner can be bought and the codes read by the owner or they can take the vehicle into a shop.
I'm certainly NOT a mechanic but .... since the trouble codes are stored in the vehicle's on-board computer I doubt that there IS any way to retrieve them without a device and a program that can "read" the car's computer.
To read the computer codes on a 1988 Mazda 323, you need to connect a jumper wire between the terminals of the diagnostic connector located under the dashboard. Once connected, turn the ignition key to the "On" position without starting the engine. The check engine light will then start to blink, where the number of blinks corresponds to specific trouble codes. Count the blinks and refer to the vehicle's service manual to interpret the codes.
To read the trouble codes in a 1993 Ford Topaz, you need to locate the diagnostic connector, usually found under the dashboard near the driver's side. Once you find the connector, you can use a code reader or jumper wire to extract the trouble codes, which will flash on the check engine light. Refer to a repair manual specific to your vehicle to interpret the codes.