Automotive electronics diagnostics
1. Visual inspection
* Check the battery for corrosion and loose connections.
* Inspect the wiring for damage, breaks or kinks.
* Check fuses and relays for blown or damaged ones.
2. Multimeter/SCANNER
Voltmeter:
*Check battery voltage (usually 12-14V).
* Check the alternator voltage with the engine running (usually 13.8-14.5 V).
* Check voltage at various sensors and actuators (refer to service manual).
Ammeter:
* Check the leakage current when the motor is turned off (no more than 50 mA).
* Check the load current when turning on various systems (eg headlights).
Ohmmeter:
* Check wiring and component resistance for opens or shorts.
* Check the resistance of the sensors and actuators (refer to the service manual).
SCANNER:
* Read fault codes stored in the electronic control unit (ECU).
* Perform bidirectional tests (eg turning components on and off).
* Display sensor readings and parameters in real time.
3. Inspection of electronic components
* Check connectors for corrosion, loose connections or damaged contacts.
* Check transistors, diodes and other electronic components for damage or short circuit.
* Examine the electronic control unit boards for damage to the tracks or soldering.
4. Special tools
* Circuit test lamp for checking circuits for continuity.
* Specialized software for diagnostics and calibration of complex electronic systems.
* Oscilloscope for analyzing electrical signals and identifying faults.
5. Diagnostics of on-board systems
* Ignition system: Check the spark plugs, ignition coils, ignition module, and crankshaft and camshaft position sensors.
* Power system: check injectors, lambda probes and mass air flow sensors.
* Charging system: check battery, alternator and voltage regulator.
* Air conditioning system: check the compressor, thermostatic expansion valve and temperature sensors.
Notes:
*Always refer to the service manual for your specific vehicle make and model.
* Diagnosing automotive electronics can be a complex process that requires specialized knowledge and equipment.
*If you do not have electrical experience, it is recommended that you contact a qualified automotive electrician.