Common Failures in Auto Electronic Components
Here are some popular car electronic components that are known to fail relatively often, especially in older or heavily-used vehicles:
1. ECU/PCM (Engine or Powertrain Control Module)
Symptoms of failure: check engine light, poor fuel economy, misfiring, starting issues.
Causes: power surges, water damage, or aging components.
Repairable? Yes, often.
How? Reflowing/replacing damaged ICs, repairing power circuits, updating firmware.
2. Mass Air Flow (MAF) Sensor
Symptoms of failure: rough idling, poor acceleration, stalling, high fuel consumption.
Causes: dirt buildup, wear over time.
3. Throttle Position Sensor (TPS)
Symptoms: hesitation, stalling, erratic acceleration.
Causes: wear and tear, contamination.
4. ABS Control Module
Symptoms: ABS warning light, loss of anti-lock braking, unusual braking behavior.
Causes: corrosion, failed internal circuits, or sensor faults.
5. Electronic Ignition Coils
Symptoms: misfiring, engine hesitation, hard starts.
Causes: overheating, moisture ingress.
6. Body Control Module (BCM)
Symptoms: malfunctioning windows, lights, locks, or dash indicators.
Causes: water intrusion, power surges, aging solder joints.
7. Alternator (with built-in voltage regulator)
Symptoms: dim lights, battery not charging, electrical accessory issues.
Causes: bearing wear, diode failure.
8. Instrument Cluster
Symptoms: flickering gauges, inaccurate readings, total blackout.
Causes: solder cracks, capacitor failure, or moisture.
Repairable? Yes.
How? Replacing backlight, repairing ribbon cables, fixing bad solder joints, replacing processors or screens.
Common repair: BMW pixel issues, VW LCD flickering.
9. Hybrid/Electric Vehicle Inverter or Battery Control Module
Why it fails: high voltage stress, overheating, component aging.
Common in: Prius, Tesla, and other hybrids/EVs.
Repairable? Sometimes.
How? Replacing IGBT modules, blown capacitors, or bad sensors.
Limitations: High-voltage safety requirements and proprietary parts make it harder.
10. Advanced Driver Assistance Systems (ADAS) Modules
Examples: Lane Keep Assist, Adaptive Cruise Control, Collision Avoidance Systems.
Why they fail: sensor misalignment, internal software errors, damage from minor impacts.
11. Air Suspension Control Modules and Sensors
Why it fails: sensor failure, moisture, software issues.
Vehicles affected: Range Rover, Audi Q7, Mercedes-Benz S-Class.
Repairable? Sometimes.
How? Fixing relay faults, moisture damage, or bad MOSFETs on the board.
12. Transmission Control Module (TCM)
Why it fails: fluid contamination, heat, faulty sensors.
Effects: harsh shifting, no shifting, limp mode.
Repairable? Yes, but complex.
How? Replacing failed solenoids, capacitors, or repairing PCB.
Common for: VW DSG (Mechatronic), Mercedes 722.6 TCU.
13. Infotainment System / Navigation Unit
Why it fails: software corruption, internal power issues, display failure.
Common in: Audi MMI, BMW iDrive, Tesla screen modules.
Repairable? Yes.
How? Replacing internal SSDs, fixing audio amp ICs, reflowing boards, display replacement.
Issues fixed: Frozen screens, no sound, non-responsive UI.
14. ADAS Camera or Radar Modules (e.g. front radar for ACC)
Cost: NZD $1,000–$3,500
Why it fails: damage, calibration failure, software bugs.
Common in: high-end Japanese and European vehicles.
Repairable? Rarely.
Why? Proprietary calibration, sealed units, and strict alignment requirements.
When possible: Repairs focus on cracked lenses, board-level faults.
15. Keyless Entry / Start Modules
Symptoms: failure to detect key fob, no start.
Causes: wireless interference, dead fob battery, receiver faults.
16. Oxygen Sensors (O2 Sensors)
Symptoms: high emissions, check engine light, poor fuel economy.
Causes: carbon buildup, aging.
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