Trouble Codes Help


Reading Trouble Codes

To read codes, open the Diagnostics > Trouble Codes page and codes will be read automatically. You can refresh the codes by pressing Menu > Refresh.

Unless you are using enhanced diagnostics, only emissions-related trouble codes that cause the check engine light to illuminate will be read.


Understanding Trouble Codes

Vehicles include sophisticated monitoring systems that detect when faults occur and can alert you of the problem by illuminating a dashboard light, such as the check engine light (MIL). Functionality of the monitoring systems vary based on the implementation for your specific vehicle. In general, when a fault has been detected, a Pending code will be set by the monitoring system. When the fault has been active for a long enough time or through multiple drive cycles, the Pending code will mature to a Confirmed code. A Confirmed powertrain code will cause the check engine light to illuminate, indicating that your vehicle has confirmed a problem with the powertrain or emissions system. When the check engine light is ON, it's a good idea to read the trouble codes to help determine the cause and severity of the problem. In some cases, the cause could be as simple as a loose gas cap. In other cases, the problem could pose a risk to the health of your vehicle and result in poor fuel economy. If the check engine light is blinking, you have a serious problem with the vehicle and need to get it fixed immediately!

Confirmed Code

A confirmed code is set when a fault has been continuously active for a specific monitoring routine and is matured enough in the current operation cycle.

Pending Code

A pending code becomes active only if a fault reoccurs a certain number of times in a certain number of drive cycles. The number of reoccurrences and the number of drive cycles depends on the fault.

Permanent Code

A permanent code is a confirmed code that cannot be cleared using a scan tool. Permanent codes will be cleared by the vehicle when the vehicle detects that the fault causing the code is no longer occurring.

Current Code

A current code is indicated when a DTC test fails on the current operation cycle. A current code could also be pending or confirmed, but does not have to be pending or confirmed.

Historical Code

A historical code is indicated when a DTC is not pending, confirmed, or current, but the associated DTC test has completed and failed at least once since codes were last cleared.


Clearing Trouble Codes

You should only clear codes with the ignition ON and the engine OFF. You should never try to clear codes with the engine running.

Before you clear trouble codes, make sure you have fixed the problem that is causing the code. If the problem has not been fixed, the fault will most likely be re-detected by the vehicle and the code will reappear. When you clear trouble codes, the vehicle will reset other information such as the status of monitoring tests, fuel trims, and any stored freezes frames. It's a good idea to understand the cause of the fault and to fix the problem before clearing codes, as important diagnostic information can be lost when codes are cleared.

Note that Permanent trouble codes cannot be cleared with any scan tool. Permanent codes will be cleared by the vehicle when the vehicle detects that the fault causing the code is no longer occurring.

Unless you are using enhanced diagnostics, only emissions-related trouble codes that cause the check engine light to illuminate will be cleared.

To clear codes, open the Diagnostics > Trouble Codes page, then press Menu > Clear Trouble Codes.