When a vehicle is brought in for repairs, the technician should begin the repair process by checking to see if the vehicle diagnostics and or vehicle electronics have been damaged as a result of a collision or comprehensive loss. A pre-scan of the vehicle can identify all of the Diagnostic Trouble Codes (DTC) present and provide explanations of each code before the repairs begin. However; often due to the condition of the vehicle the vehicle’s battery is showing a low voltage, this condition may not allow all of the modules to be read, thus affecting the quality of the scan and the accuracy of the report. For this reason, battery support is necessary when scanning a vehicle.
Before the scan
To obtain the highest quality scan, the first, and arguably the most important step is to provide proper battery support to the vehiclebefore beginning the diagnostic and vehicle electronic scan process. A battery voltage maintainer is the best choice. Battery chargers or a jump box are not recommended as they will not provide the proper battery support to the vehicle. Battery chargers can overcharge and “cook” a battery, and jump boxes can go dead or lose their charge over time.
The car should be in “key on-engine off” (KOEO) mode, and the battery must be supported and kept at a constant voltage. Why is this step so important? If the battery voltage drops below certain levels, the battery will start to shut down non-essential modules to preserve the ability to start the car. Low voltage can create a situation where the scan tool might not be able to read all of the available modules. Connecting a proper battery support tool to the vehicle battery will ensure that the battery will provide consistent voltage which will allow the technician to provide the highest quality report and information for the repair facility.
Advantages of battery support
A quality battery voltage maintainer provides uniform voltage to the vehicle for longer periods of time compared to an unsupported battery. The bottom line is to make sure that before you begin any diagnostic or vehicle electronic scan device, that the car has proper battery support to provide the best possible outcomes.
When vehicle voltage levels fall below the normal levels, diagnostic results are no longer accurate. Fluctuations in battery voltage can also cause additional codes to appear. If an unsupported battery fails, or fluctuates, during programming it can cause the programming to fail, which can be very costly.
Needed for both pre- and post-scan
To recap, only when the vehicle has proper battery support, can the technician perform the proper diagnostic and vehicle electronic scans. A stable battery voltage ensures that the technician can generate the quality scan results and corresponding reporting necessary to provide the information needed to produce an accurate, efficient, and safe repair. At the post scan stage, battery support is required to ensure that all codes can be cleared and additional codes aren’t introduced due to voltage fluctuations. Key On Engine Off (KOEO) combined with a stable and supported battery are the first steps to take before every scan.