Build the case before choosing a direction
Start with the vehicle, complaint, symptoms, DTCs, operating conditions, recent work, available tools, and any measurements already completed.
STEP Diagnostics for mechanics
Stay on the diagnostic path—from the first symptom to a verified repair
STEP is being built for mobile mechanics and independent technicians who need a clearer way to work through difficult diagnostic cases. It keeps the vehicle context, service information, completed tests, and results together—then helps determine the next relevant check as new evidence comes in.
One working case
Evidence stays connected
01Vehicle + concern
02Confirmed context
03Next relevant check
04Actual test result
05Repair verification
Diagnostic reality
Difficult diagnoses rarely fail because information does not exist
The information may already be available in scan-tool data, wiring diagrams, diagnostic procedures, connector views, specifications, technical service bulletins, and previous test results.
The difficult part is keeping the complete case together.
- the exact vehicle and configuration
- the customer’s concern and the conditions under which it occurs
- active, pending, history, and permanent DTCs
- recent repairs, modifications, or battery events
- tests already performed and their actual results
- relevant components, circuits, connectors, grounds, and power feeds
- the next question that must be answered before the diagnosis can move forward
When that context is lost, tests get repeated or skipped, assumptions begin to look like facts, and the job can drift toward replacing parts before the fault has been demonstrated.
One working case
One working case instead of disconnected information
STEP is designed to organize the complete diagnostic process around the evidence available for that vehicle.
Work through one clear diagnostic step at a time
Receive a defined next check with the reason it matters, the required conditions, the expected result, and the information that should be returned.
Keep every result attached to the case
Measurements, observations, scan data, images, completed checks, and repairs remain part of the case instead of disappearing between notes, browser tabs, and conversations.
Change direction when the evidence changes
A diagnostic plan should not remain fixed after a measurement disproves the current hypothesis. STEP is designed to reassess the case and select the next relevant check without erasing the earlier history.
Verify the original concern after repair
A repair does not automatically close the case. The repaired condition, original symptom, and remaining DTCs still need to be checked.
Guided workflow
How the guided workflow works
- 01
Establish the vehicle and concern
Enter the best available vehicle details, customer complaint, symptoms, DTCs, operating conditions, recent work, and existing test results.
- 02
Review the case summary
Separate customer-reported information, technician observations, measured results, and unresolved questions before beginning the diagnostic path.
- 03
Receive the next relevant check
STEP uses the current case evidence and available service information to present one clear next diagnostic step.
The step can include:
- the purpose of the check
- the required tool
- the correct operating conditions
- the component, connector, or circuit involved
- the expected result
- the applicable source
- 04
Perform the test and enter the result
Return the actual measurement, observation, scan data, photo, or other requested evidence. An unperformed test is not treated as a failed test, and an unknown value is not used to support either diagnostic branch.
- 05
Continue, reassess, or repair
The next step changes according to the result. A hypothesis may be supported, rejected, narrowed to a specific circuit, or replaced by a more relevant direction.
- 06
Verify the repair
After a repair, STEP keeps the case open until the repaired area and the original customer concern have been checked.
Beyond the DTC
More than a code lookup or a list of possible causes
A DTC identifies a condition detected by a module. It does not prove that the component named in the code has failed.
STEP is designed to help the technician separate those possibilities through actual checks rather than turn a list of common causes into a diagnosis.
The workflow can also begin without a DTC. Symptom-based cases can start from the reported condition, operating circumstances, recent work, and observable system behavior.
A single circuit code may be caused by:
- a missing power supply
- a poor ground
- an open or shorted circuit
- connector damage
- an incorrect signal
- a failed component
- a module input or control problem
- another condition affecting the same system
Professional workflow
Built for real diagnostic work
Mobile mechanics
Keep the complete case available when the vehicle, customer, and work location change throughout the day.
Independent technicians
Work through difficult cases without building the diagnostic trail across handwritten notes, screenshots, browser tabs, and memory.
Shop technicians
Preserve a case that another technician or service advisor can understand when a handoff is required.
Repeat and intermittent problems
Retain the exact sequence of symptoms, operating conditions, checks, results, repairs, and verification instead of starting over when the vehicle returns.
Service information remains part of the process
Repair-information platforms and manufacturer resources provide essential:
- diagnostic procedures
- wiring diagrams
- connector views
- specifications
- component locations
- technical service bulletins
- programming and service instructions
STEP is not being built to replace those sources.
Its role is to connect the relevant information to the active diagnostic case, preserve the result of each check, and help the technician maintain a clear path from the original concern to a verified repair.
Vehicle-specific information—such as connector pins, circuit numbers, expected values, and test conditions—should remain linked to the applicable source.
The technician remains in control
STEP can organize the case, present relevant service information, propose a diagnostic step, preserve evidence, and adjust the working plan when new results are entered.
The technician still determines whether a proposed procedure is appropriate for the vehicle and working conditions, performs or supervises the test, evaluates the physical evidence, and makes the final repair decision.
STEP does not replace professional training, current manufacturer procedures, equipment instructions, or required safety practices.
Read the Diagnostic MethodologyCurrent status
STEP is preparing for technician early access
STEP is currently a working prototype preparing for technician early access.
Current development is focused on:
- one-step-at-a-time guided diagnostic cases
- DTC- and symptom-based workflows
- structured case history and evidence
- source-linked diagnostic procedures and vehicle information
- broader validated vehicle coverage
- repair and verification workflows
STEP is not yet a generally available production diagnostic service.
An interactive trial is planned for October 2026, subject to product-readiness approval. Early access will open in stages to technicians whose work matches the available workflow and vehicle coverage.
Frequently asked questions
Questions from working technicians
Is STEP available now?
STEP is preparing for early access and is not yet a generally available production diagnostic service. Access will open in stages based on technician needs, validated workflow coverage, and supported vehicles.
How is STEP different from a normal AI chatbot?
A normal chatbot usually answers from the current message and may return a general list of possible causes.
STEP is being designed to preserve the complete diagnostic case, use applicable service information, issue one defined next step, record the actual result, and change the diagnostic direction when the evidence changes.
Does STEP replace ALLDATA, Mitchell 1, or manufacturer service information?
No. Those platforms provide essential service and repair information. STEP is designed to organize the diagnostic workflow around that information and the evidence collected from the vehicle.
Does STEP diagnose the vehicle automatically?
STEP can form working hypotheses, identify relevant checks, and update the diagnostic plan based on the results entered.
The technician performs or supervises the physical tests, determines whether they are safe and appropriate, evaluates the evidence, and makes the final repair decision.
Can a case begin without a DTC?
Yes. The planned workflow can begin with a DTC, a symptom, or a combination of both. The absence of DTCs does not mean that no fault exists.
Can STEP show wiring diagrams, connector information, or component locations?
The planned workflow can provide relevant diagrams, connector views, pin information, component locations, and test values when those resources are available for the selected vehicle and case.
Which vehicles are supported?
Coverage is still being expanded and validated. The published diagnostic library shows the vehicle-specific guides currently available on the STEP website. Early-access coverage may differ and will be explained during onboarding.
What happens after I request early access?
STEP collects your contact details, professional role, and optional information about the type of diagnostic work you perform. As testing opens, prospective users whose needs match the available workflow and vehicle coverage will be contacted.
Help shape STEP Diagnostics
Diagnose difficult cases without losing the thread
Request early access to test STEP with real diagnostic cases and help shape a guided workflow built around the way working technicians diagnose vehicles.