The Best Body Shops’ Tips: Best Practices When Interpreting & Documenting Scan Data, Trouble Codes & Calibrations

The Best Body Shops’ Tips: Best Practices When Interpreting & Documenting Scan Data, Trouble Codes & Calibrations

Today’s vehicles and those manufactured over the last two decades contain a wealth of electronic information that can help shops effectively and efficiently perform a proper repair, according to Chuck Olsen, executive director of AirPro Diagnostics.

“If we don’t look for all of the clues there are within the system, it will make the job much more difficult than it has to be,” he said.

As a result, Olsen said, a capable scan tool is a critical component of strategy-based diagnostics.

“They give order and method on how we diagnose, service and reprogram vehicle control modules on these increasingly complex inter-related systems to restore vehicles to sound operation condition,” he explained.

With more than 40 years of experience in the automotive repair and technology industry, Olsen recently shared insights on interpreting and documenting scan data, trouble codes and calibrations during a CIECAst webinar.

The following is a summary from the presentation:

What is essential to know about scan tools today?

For many in the industry, there’s a certain mystique in relation to using a scan tool and what they can do. Scan tools are engineered and designed to be directly connected to the vehicle utilizing the most current diagnostic software available. Depending on the tool, it might only read out diagnostic trouble codes (DLCs) or can have additional capabilities such as calibrating or programming modules. Most scan tools require a pass-through device with a subscription to an OEM provider to fully reprogram the modules.

Scan tools have many functions and ways they can be used, but the most common is doing a pre-scan, post-scan or what is known as a health check of a car. This is always the starting point.

By no means are scan tools and scan tool data definitive or infallible. Understanding and being able to fully employ the functionality available to us with modern and emerging scan tools are acquired skills. It’s important that our knowledge and skills keep pace with technology changes and the associated scan tool functionality.

Can you share some of the differences between an aftermarket and OEM scan tool?

I’m often asked this question. Aftermarket top tier scan tools are now competitive with OEM dealer scan tools; however, they are not exactly the same. I’m not an advocate of one over the other. It’s necessary to understand their capabilities and the strengths and weaknesses of each.

There is no one aftermarket or OEM scan tool that can do everything on all vehicles. The key is in the mix of vehicles that you are repairing or servicing. You’ll want to look at the brands your shop specializes in, if any, and then use the correct tool or service for the job at hand. There are certain functions, procedures and OEM certification requirements that will dictate when OEM scan tool applications are your only option.

The one caveat is to make sure you know what your tools can and cannot do. In certain instances, some functionality may have to be given up in order to achieve a lower price point or you’ll need to access the dealer tool. Be honest with yourself about what your shop cannot do and be prepared to sublet or decline the job if it’s the best option. Remember that honesty still resonates as a reason your customers do business with you.

What needs to be analyzed when you are going through a strategy-based diagnostics process?

First, it’s important to visually inspect the car and determine what is broken, damaged, leaking, etc. Next, look at the symptoms of what is not working properly, such as the malfunction indicator lamps or system functional checks. The third step is to reference the service information. This includes the inspection requirements, repair procedures, testing procedures, option content and calibration requirements. Finally, it’s time to check the electronic data from the vehicle. This includes using a capable scan tool to determine the DTCs, live data stream values and calibration verification.

What is important to know about accessing the raw electronic data from the scan tool?

The raw data is managed by several different specifications and can be characterized as languages that the vehicle must adhere to in order to communicate. You need a tool that can speak these languages. The software adopted by all OEMs allows the independent aftermarket the ability to reprogram, diagnose and access data from the electronic control units (ECUs) without the need for a dealer-only tool. The OEMs provide the scan tool application programs available for independent purchase with user license agreements.

Why should a shop always conduct research?

For every single repair, research is required. That can be sourced from the OEM as well as third-party suppliers that purchase the service information and repost it. There will be times you’ll have to go to the OEM direct subscription to obtain the latest updates. You must review every repair and procedure performed on a vehicle to identify calibration or programming procedures that will need to be performed with a scan tool and also to determine that the scan tool being used is capable of the procedure.

Part of this is knowing that most times, scanning a car is not going to alert you that a calibration is needed or must be performed. This is almost always found in the service information. The only exception is if a component has been replaced that has never been calibrated. In this instance, we’ll often see a code set for a calibration requirement, but you can’t count on it.

It’s imperative that you review the repair procedures and find out if a calibration needs to be done. You’ll then need a capable scan tool and, in many cases, additional equipment such as targets or seat weights to execute that calibration.

Is it common for a scan tool to miss a DTC?

With the complexity of today’s vehicles, there is always the chance for a scan tool to miss control units or DTCs during a general health check. There are two distinct reasons for this.

First is that the non-reporting control units can be filtered out by some scan tools. Although it is rare, you must be aware of it when using a scan tool independently or relying on a service.

This is normally caused by an impact at or near the area of the control unit, damaged wiring harness, connector damage, blown fuses or poor ground connections.

Another reason is due to a busy automotive network or the control unit returning information slowly because of a large amount of data stored in that module. Modules have timing parameters that must be adhered to, and at times while they are returning large trouble code records, that request can time out and the scan tool will move on and possibly miss something.

This is when it is necessary to check systems individually on a vehicle or go back and rerun a scan multiple times to make sure everything was received. Both OEM and aftermarket scan tools can be subject to this and is why there are so many update requirements with scan tools.

Why should repairers be aware of the build list in the software’s internal database?

When you are reading the scan tool data, be aware that the wrong options can sometimes be reported in the scan tool database. Where we usually see this happen is when there are added accessories or option modifications done by the dealership or the aftermarket. An example is if a customer wants foglamps installed at the dealership; these will not be included in the vehicle option content list and may or may not be accessible by a scan tool. As a result, you must do an inspection and pay close attention to what optional equipment is included.

How can they overcome these issues?

DTCs are just the starting point of drilling down the problem(s) on a vehicle. Each system is made up of a group of components, and it’s important to be aware of them during the diagnosis. We call it Component Level Scanning (CLS). This is much different than just reading trouble codes. With CLS, we get as close to the raw or live data as possible.

CLS gives us a complete picture of the health of the system. In fact, we can determine faults from data streams before they are reported as a DTC by the control unit.

What should be included in the documentation?

Once the car has been repaired, it’s crucial to document everything. This includes what we started with and what we found, what parts we replaced and/or repaired, as well as removed and reinstalled. Also, document what the OEM service information says, the diagnostic procedures and calibrations performed, the functional quality control test results, and even what we did not do---the non-related issues on a vehicle. Documentation helps protects the customer and your business.

What steps should my business take when it comes to privacy?

A customer needs to know you are going to be accessing data from their vehicle. My advice when it comes to privacy is to incorporate a statement for the customer into your work authorization form and let him or her know you are going to be accessing all types of data to repair the car properly and/or to make decisions on insurance, warranty or customers’ responsibilities.

Stacey Phillips Ronak

Stacey Phillips Ronak is an award-winning writer for the automotive industry and a regular columnist for Autobody News based in Southern California.

AkzoNobel Beta web graphic v2 600px

Shop & Product Showcase