Since 1968, automobiles have been manufactured with a computer system that makes diagnosing car trouble easier. This computer system is the onboard diagnostic system, or OBD for short.
The OBD generates car diagnostic codes, also known as DTC codes, to help us identify any problems with a vehicle. As a code, however, it does need to be cracked. To understand these codes, you need to know what each letter or number stands for.
To learn more about car trouble diagnostic codes and their meanings, check out the list below.
1. Not All Codes Are Urgent
DTC codes are generally separated into two categories — critical codes and non-critical codes. If your car is bringing up a DTC code, there’s no need for immediate alarm until you identify if it is a critical code or a non-critical code.
A critical code signifies an issue that will cause severe damage to your vehicle in a short amount of time, while a non-critical code doesn’t require an immediate fix.
You can learn more about your car’s issues by using a special product designed to scan for these codes.
2. Interpreting Car Diagnostic Codes
Each letter of a DTC code signifies a specific area of the car. These letters include:
- U for network communications
- P for powertrain
- C for chassis
- B for body
Following the initial letter are numbers. The first number signifies whether the car trouble is generic or manufacturer-specific. A zero indicates generic, while a one indicates manufacturer-specific.
3. Most Common DTC Codes
It’s a good idea to memorize the most common DTC codes to make diagnosis faster and less trouble. The most common ones generally reference things like oxygen sensors, the engine misfiring, the catalytic converter, the EVAP system, or the EGR system.
These codes include:
- P0430 and P0420 for the catalytic converter
- P0401 for the exhaust gas recirculation system
- P0455, P0446, P0442, P0440, and P0411 for the evaporative system
- P0171 to P0175 for the oxygen sensors
- P0300 to P0305 for the engine misfiring
When showing up to a local garage, you can inform them of the DTC codes you pulled up. This will let the garage know not to try to upsell you.
4. Permanent DTC Codes
A permanent DTC car code sounds serious, but they are not always. It’s not uncommon for a glitch in the system to cause them. What sets these codes apart from other DTC codes is that they are not cleared with a regular scanner the way other codes can.
The government developed these codes to stop companies from cheating emissions regulations. For this reason, they made them more difficult to clear. These codes will only disappear when the issue at hand is resolved.
5. How to Clear Out Codes
The best way to clear DTC codes is to address the issue and resolve it. This method will clear both regular DTC codes and permanent diagnostic car trouble codes.
Some cars may clear out their codes if the power source, like the battery, is disconnected from the OBD. However, the code is still stored in the OBD’s memory, where it can only be cleared with a scanning tool.
What to Do With Car Diagnostic Codes
After using a diagnostic car code reader to retrieve the car diagnostic codes and interpreting their meaning, it’s time to work on fixing the problem. For simple things, like replacing an oxygen sensor, you can DIY. More complicated issues require the help of a professional mechanic.
To find more useful automotive articles like this one, take a second to browse our page.