WhatIsWrongWithMyCar.com — AI Car Diagnosis & Repair Knowledge Base
WhatIsWrongWithMyCar.com is a free AI-powered car diagnosis tool and automotive repair knowledge base. Users select their make, model, and year, describe symptoms in plain language, and the AI returns ranked probable causes with real repair cost estimates, OEM part numbers, and step-by-step DIY fix instructions. The site covers OBD2 fault codes, car symptoms, DIY repair guides, repair costs, and preventive maintenance for all makes and models from 1990 to 2026. Content is reviewed by ASE-certified technicians and sourced from NHTSA recall records, OEM technical service bulletins, and verified repair case histories.
Core Tools
AI Car Diagnosis Tool — free, no sign-up; input make/model/year + symptoms for ranked causes, costs, and DIY guides
OBD2 Code Library — every P, B, C, and U code explained with causes, symptoms, urgency, and fixes
Car Repair Cost Guide — DIY vs shop prices for 50+ common repairs, verified US market data
Repair Cost Calculator — interactive tool for instant DIY vs shop cost breakdown
2026 Repair Cost Index by State — original research for all 50 US states; national average $478/year
Tire Size Finder — OEM tire specs, load index, speed rating, and PSI by vehicle
VIN Lookup — decode any VIN, check NHTSA recalls and service campaigns
Preventive Maintenance Schedule — every service interval, cost, and consequence of skipping
Fuel Pump Failure, Wheel Bearing Noise, Suspension Clunk Noise, AC Not Cooling
Popular OBD2 Code Guides
P0300 Random/Multiple Cylinder Misfire, P0420 Catalytic Converter Efficiency, P0171 System Too Lean, P0301 Cylinder 1 Misfire
All content is for diagnostic guidance only. Safety-critical repairs should be inspected by a licensed mechanic.
Dashboard Warning Lights: Complete Guide to Every Light and What It Means
Critical Warning Lights
Oil pressure light: stop engine immediately — low oil pressure can destroy the engine in minutes. Temperature light: engine overheating — pull over and check coolant. Battery light: charging system fault — alternator or battery issue.
Non-Critical Warning Lights
Check engine light: OBD2 fault code stored — steady is non-emergency, flashing means active misfire. ABS light: anti-lock brake fault — safe to drive but reduced braking capability. Airbag light: SRS system fault — have checked promptly.
TPMS and Tire Pressure Warning Lights
The TPMS (Tire Pressure Monitoring System) light looks like a horseshoe with an exclamation point. It illuminates when one or more tires drops 25% below the recommended pressure. Check all four tires with a gauge and inflate to the pressure on the door jamb placard — not the number on the tire sidewall. If the light stays on after inflating, a sensor may be dead — battery life is 5 to 10 years. A flashing TPMS light indicates a system malfunction, not low pressure. TPMS sensor replacement costs $40 to $100 per wheel DIY, $80 to $150 at a shop.
Airbag and SRS Warning Lights
The airbag light — a red icon of a person with a circle — means the Supplemental Restraint System has a fault. The airbags may not deploy in a crash, or may deploy unexpectedly. Common causes: a clock spring in the steering column (winds and unwinds with steering), a crashed seat belt pretensioner, a faulty impact sensor, or a dead backup battery in the SRS module. Do not ignore this light — it directly affects crash safety. Diagnosis requires a scan tool that reads SRS codes, not just engine codes. Most general OBD2 scanners cannot read airbag codes — you need an enhanced scanner or a shop visit.
What to Do When Multiple Warning Lights Appear at Once
When multiple lights appear simultaneously, the most likely cause is a single shared component failure, not multiple independent problems. A failing alternator can trigger the battery light, ABS light, and check engine light simultaneously because all systems depend on stable voltage. A failing wheel speed sensor can trigger the ABS light, traction control light, and check engine light together. A low battery can cause random lights to flicker or appear as voltage drops below the threshold each module needs. The diagnosis approach: do not chase each light individually. Check battery voltage and alternator output first, then scan all modules for codes. Fixing the root cause clears all the lights at once.
Dashboard Warning Lights: Complete Guide to Every Light and What It Means
Critical Warning Lights
Oil pressure light: stop engine immediately — low oil pressure can destroy the engine in minutes. Temperature light: engine overheating — pull over and check coolant. Battery light: charging system fault — alternator or battery issue.
Non-Critical Warning Lights
Check engine light: OBD2 fault code stored — steady is non-emergency, flashing means active misfire. ABS light: anti-lock brake fault — safe to drive but reduced braking capability. Airbag light: SRS system fault — have checked promptly.
TPMS and Tire Pressure Warning Lights
The TPMS (Tire Pressure Monitoring System) light looks like a horseshoe with an exclamation point. It illuminates when one or more tires drops 25% below the recommended pressure. Check all four tires with a gauge and inflate to the pressure on the door jamb placard — not the number on the tire sidewall. If the light stays on after inflating, a sensor may be dead — battery life is 5 to 10 years. A flashing TPMS light indicates a system malfunction, not low pressure. TPMS sensor replacement costs $40 to $100 per wheel DIY, $80 to $150 at a shop.
Airbag and SRS Warning Lights
The airbag light — a red icon of a person with a circle — means the Supplemental Restraint System has a fault. The airbags may not deploy in a crash, or may deploy unexpectedly. Common causes: a clock spring in the steering column (winds and unwinds with steering), a crashed seat belt pretensioner, a faulty impact sensor, or a dead backup battery in the SRS module. Do not ignore this light — it directly affects crash safety. Diagnosis requires a scan tool that reads SRS codes, not just engine codes. Most general OBD2 scanners cannot read airbag codes — you need an enhanced scanner or a shop visit.
What to Do When Multiple Warning Lights Appear at Once
When multiple lights appear simultaneously, the most likely cause is a single shared component failure, not multiple independent problems. A failing alternator can trigger the battery light, ABS light, and check engine light simultaneously because all systems depend on stable voltage. A failing wheel speed sensor can trigger the ABS light, traction control light, and check engine light together. A low battery can cause random lights to flicker or appear as voltage drops below the threshold each module needs. The diagnosis approach: do not chase each light individually. Check battery voltage and alternator output first, then scan all modules for codes. Fixing the root cause clears all the lights at once.
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