Practical Video 01
An insight into technical diagnostics
Vehicle diagnostics
From fault code to the actual root cause
Professional diagnostics starts with the symptoms and ideally ends with a clear, evidence-based technical finding. Diagnostic data, measured values and, where necessary, electrical signals are assessed together.
Technical Information
Diagnostics Explained Clearly
Vehicle diagnostics involves more than reading fault memory. Diagnostic systems combine control unit data and vehicle functions and, where supported, allow analysis of data-bus communication. This provides a technical basis for further fault-finding.
Bus Systems
CAN, LIN, MOST & FlexRay
Why modern vehicles rely on networked control units and how communication faults affect diagnostics.
Diagnostics
Guided and logical diagnostics
What diagnostic systems can do and why technical root-cause analysis may need to go beyond the stored fault code.
Measurement Technology
Oscilloscope & signal analysis
Make electrical signals visible, compare them and assess them under real operating conditions.
Diagnostic Levels
Structured diagnosis instead of replacing parts on guesswork
Depending on the vehicle and symptoms, diagnostics may involve several levels. Fault memory and live data are the starting point; measurements and signal analysis help narrow down the cause when necessary.
Fault Memory & System InformationEvaluate stored faults, freeze-frame data and relevant system information.
Live Data & Actuator TestsCheck live operating values and activate components where supported.
Electrical TestingMeasure and examine power supplies, grounds, wiring and signals.
Logical DiagnosticsEstablish relationships between symptoms, measured values and system responses.
OEM Diagnostic Systems & Multi-Brand Diagnostics
The Right Diagnostic Level for Every Vehicle
Depending on the vehicle, OEM diagnostic systems and multi-brand diagnostic tools are used. These include, among others, Mercedes-Benz XENTRY, BMW ISTA and Volkswagen Group ODIS. The diagnostic approach depends on the vehicle, the system and the symptoms.
OEM systems often provide the most detailed vehicle-specific information. If guided diagnostics is not sufficient, it is supplemented by independent technical testing.
Logical Diagnostics
A fault code describes a condition—not necessarily a defective component.
A modern vehicle is a networked system: control units exchange information, sensors provide status data and actuators carry out commands. A fault code may identify an affected area, but it does not automatically determine the root cause.
A stored fault code is an important clue, but it can have several possible causes: a sensor may be defective, its power supply may be missing, a wire may be open-circuit, or communication between control units may be disrupted.
Fault codes, live data, system responses and vehicle behaviour are therefore compared. Reliable diagnostics combines system knowledge, measured values, electrical testing and observation of the vehicle in operation.
Symptoms → Information → Measurement → Root Cause
The individual diagnostic levels are not considered in isolation, but combined to build a coherent technical picture.
The individual diagnostic levels are not considered in isolation, but combined to build a coherent technical picture.
Example:
A fault associated with a sensor does not necessarily mean that the sensor itself is defective. The root cause may also be the power supply, ground connection, wiring, connector or the way the control unit processes the signal.
A fault associated with a sensor does not necessarily mean that the sensor itself is defective. The root cause may also be the power supply, ground connection, wiring, connector or the way the control unit processes the signal.
Measurement Technology
Signals and Measured Values Made Visible
When diagnostic information alone is insufficient, direct measurement of electrical signals can be decisive. An oscilloscope reveals waveforms, frequencies, signal levels, timing relationships and deviations from expected behaviour.
The relevant factors are not only individual voltage readings, but also waveform shape, frequency, timing and behaviour under load. Measurements can be compared with expected system behaviour and the actual symptoms.
- Sensor and actuator signals
- Power supply and ground
- Wiring and signal quality
- Signal Timing Relationships
- Bus and communication signals
MeasurementWhat Is Actually Happening Electrically?
ComparisonDoes the Signal Follow the Expected Pattern?
CorrelationDoes the Measurement Match the Symptoms and Observed Vehicle Behaviour?
In-Vehicle Communication
When control units communicate
Modern vehicles contain many networked control units. CAN, LIN, MOST, FlexRay and other communication networks may be relevant to diagnostics.
Faults do not necessarily originate in the control unit that reports them. Communication faults, power-supply issues or breaks in the wiring network can cause secondary faults in several systems. Communication analysis is therefore an important part of technical diagnostics.
CANA widely used vehicle bus for communication between many control units and functions.
LINA simpler bus for subordinate components and functions.
MOSTA network for data transmission in infotainment and multimedia systems.
FlexRayHigh-performance communication for time-critical applications.
K-LineAn older diagnostic communication system that may still be technically relevant in many vehicles.
Communication AnalysisInclude bus behaviour, signals and system relationships in the technical analysis where necessary.
Identifying Consequential FaultsSeveral stored faults may share a common root cause.
Root Cause Analysis
From symptoms to a clear technical finding
Findings from diagnostic tools, measurements and practical testing are assessed together. The aim is not to replace as many parts as possible, but to narrow down the root cause sufficiently to determine a sound repair strategy.
01
Symptoms
Record symptoms, history and operating conditions.
02
Information
Analyse fault memory, live data and system information.
03
Measurement
Verify signals, wiring, sensors and components.
04
Root Cause
Combine the results and establish a technical finding.
Diagnostics in Practice
A closer look at measurements and fault-finding
Practical videos on the BECKER-SYSTEMS YouTube channel show what technical diagnostics and fault-finding look like in real situations.
Practical Video 02
Measurement and fault-finding in practice
Practical Video 03
Diagnostics and Technical Root Cause Analysis
Diagnostics Pricing
Diagnostics Based on Time Required and Depth of Testing
The different price tiers provide a transparent overview of the diagnostic services included in each package.
| No. | Diagnostics in Detail | Price |
|---|---|---|
| 1 | Read and Clear Fault Codes“Could you just have a quick look?” | €35.00 |
| 2 | Fault Memory and Live Data DiagnosticsDifferential diagnosis and recommended corrective action | €75.00 |
| 3 | Comprehensive DiagnosticsFault memory, live data, differential diagnosis, systems analysis, sensor and actuator measurements, CAN analysis, wiring-harness testing and root-cause identification | 1€75.00 |
| 4 | As in Package 3With Additional Mechanical Diagnostics | €250.00 |
| 5 | As in Package 4Including Microelectronics / Control Unit Diagnostics | €325.00 |
| 6 | General Electronics WorkHourly Rate | €95.00/h |
| 7 | Electronics LaboratoryLaboratory Hour | €150.00/h |
Note on Pricing: All prices are exclusive of VAT.