What does a Ford diagnostic include?
A Ford diagnostic typically involves pulling fault codes from the vehicle’s control modules using Ford-compatible tools, reviewing live data, running tests on systems, and applying software updates or recalibrations as needed. It also results in a repair plan and documented findings.
Core diagnostic elements
Code retrieval and data review
In the initial phase, technicians pull diagnostic trouble codes from all major modules and examine real-time sensor data to understand how the system is behaving.
- Retrieve fault codes from the Powertrain (ECU), ABS, Airbag/SRS, BCM, TCM, and other modules
- Read live data streams (sensor values, temperatures, pressures, voltages, speeds, pedal position)
- Review freeze frame data captured at the moment a fault occurred
- Check OBD-II readiness monitors and current drive-cycle status
- Assess communication on the vehicle’s data networks (CAN, LIN, etc.)
The codes and data form the foundation for prioritizing tests and repairs.
Diagnostic tests and actions
Following code review, technicians perform targeted tests and actions to confirm faults and verify repairs.
- Bi-directional tests and actuator tests via the scan tool to command components
- Component-level checks for sensors, actuators, solenoids, and controllers
- Data logging and trend analysis to catch intermittent issues
- Road tests or drive cycles to reproduce symptoms under real conditions
- Software updates or calibrations to ECUs/TCUs when needed
- Post-repair re-scan and verification of readiness monitors
These steps help identify root causes and confirm that repairs have resolved the symptoms.
Ford-specific tools and access
Official diagnostic platforms and access
Dealership service departments typically use Ford’s official systems to access all modules, perform advanced tests, and program updates.
- IDS (Integrated Diagnostic System) or FDRS (Ford Diagnostic and Repair System) connected to a Vehicle Communication Module (VCM)
- Access to Ford-specific DTCs, tests, and calibration updates
- Bi-directional control and flashing/software updates for control modules
- Comprehensive service bulletins, recalls, and campaign data
These tools provide the deepest level of access and reliability for Ford vehicles.
Third-party and aftermarket options
Independent shops may rely on widely used scan tools that support Ford modules and third-party Ford software for extended functionality.
- Generic OBD-II scan tools for baseline codes and live data
- Ford-focused third-party software (e.g., Forscan) for expanded module access on supported models
- Varying levels of bi-directional control depending on the tool and licensing
Tool availability and capabilities can influence the depth of diagnosis, especially for software updates and reprogramming.
What a diagnostic report typically includes
Report contents and recommendations
After diagnostics, technicians compile a report detailing codes, data, tests, and repair guidance.
- Current and stored diagnostic trouble codes (P, B, C, U) with descriptions
- Key live data snapshots and freeze frame information
- Results of functional tests and whether components passed or failed
- Recommended repair steps, parts to replace, and service actions
- Cost estimates, timeframes, and whether a re-check is advised after repair
A clear report helps customers and technicians agree on the next steps and expected outcomes.
Summary
A Ford diagnostic is a structured process that combines fault-code retrieval, live-data analysis, targeted testing, and sometimes software updates or recalibrations. It can involve official dealer systems (IDS/FDRS with a VCM) and, for some shops, authorized third-party tools. The process concludes with a documented repair plan and validation steps to ensure the issue is resolved.
What does a full diagnostic test consist of?
A full car diagnostic test involves connecting a vehicle to a computer to read error codes from its electronic systems, which checks the engine, transmission, brakes, exhaust, and other components like the fuel and electrical systems, according to Clutch Automotive, 971autogarage.com, and RAC. The test identifies problems by scanning for trouble codes stored in the vehicle's onboard diagnostic system (OBD-II) and provides detailed reports on the health of the car's various systems.
Key areas checked
- Engine: Checks the engine control unit (ECU), ignition coils, and fuel injectors for performance and issues.
- Transmission: Scans for problems affecting the transmission.
- Brakes: Inspects the anti-lock braking system (ABS) and other components.
- Exhaust and emissions: Checks the exhaust system for issues and ensures the vehicle meets emissions standards.
- Electrical and sensor systems: Diagnoses problems with the battery, charging system, and a variety of sensors throughout the car.
- Safety systems: Scans for faults in systems like the airbags.
- Other systems: Evaluates the throttle, coolant, and airflow systems.
How it works
- A mechanic connects a specialized scanning tool to the vehicle's data link port.
- The tool communicates with the car's computer to retrieve trouble codes that indicate problems.
- The technician uses this information to pinpoint issues and avoid trial-and-error repairs.
What is a diagnostic on a Ford?
A diagnostic test is simply an analysis of the car's internal computer. This computer software monitors the engine, transmission, and other components of the car. The computer adjusts the performance of the engine for optimal reliability and power output.
How much does Ford charge for a diagnostic?
Most local dealers charge a standard "diagnostics" fee, which typically ranges from $100 to $150. However, you can have the diagnostic code errors scanned for free at any major auto parts store, except in California. Alternatively, purchasing an inexpensive 'code reader' at local parts stores or online is an option.
How much is a Ford diagnostic?
The price of your Ford's diagnostic can vary, depending on the garage that you visit. Each garage offers car diagnostics for a fixed price, ranging from £30 to £100. Enter your vehicle registration number and post code into BookMyGarage to instantly compare prices on diagnostic checks from garages near you.
