Car Fault Codes Database — Every Code, Every Brand
229+ fault codes — P codes (engine / gearbox / fuel), B codes (airbag / SRS), C codes (ABS / ESP), U codes (CAN bus / network) — across BMW, Mercedes-Benz, Audi, Volkswagen, Skoda, Porsche, Mini, Volvo, Jaguar, Land Rover, Toyota, Honda, Hyundai, Kia, Tata, Mahindra, Maruti Suzuki and more.
Most Common Fault Codes in Hyderabad
Based on 16+ years of OBD-II diagnostics across 30,000+ cars, the fault codes we encounter most frequently in Hyderabad reflect the city's driving conditions — stop-and-go traffic, extreme summer heat (45 °C+), and the growing share of automatic-gearbox cars on the road. The top five codes we diagnose every week are:
- P0741 — Torque converter clutch slip. Very common in CVT-equipped Hondas, Marutis and Hyundais after 60,000 km. Slow traffic causes the lock-up clutch to slip, raising fluid temperature until the fault triggers.
- P0420 — Catalyst efficiency. Leads the board for petrol cars. In 60% of cases the real fault is a failed upstream oxygen sensor, not the catalytic converter itself — saving owners ₹15,000–₹40,000 in unnecessary parts.
- P17BF / P189C — DSG mechatronic pressure faults. Exclusive to VW, Audi and Skoda DQ200/DQ250 gearboxes. The mechatronic unit controls hydraulic pressure for all gear changes; a solenoid or valve-body fault triggers limp mode and these codes.
- P2002 / P2463 — DPF soot overload. Most common in diesel cars that do short city trips — the DPF never gets hot enough to self-regenerate. A forced regeneration on our ramp usually clears it without replacing the filter.
- P0299 — Turbo underboost. Hyderabad's dusty air and heat stress intercooler pipes and boost hoses. A boost leak test (smoke machine) pinpoints the failure in under 20 minutes and resolves 70% of P0299 cases without touching the turbocharger.
Most-Searched Fault Codes
- P0741 — Torque Converter Clutch Circuit Performance / Stuck Off
- P0420 — Catalyst System Efficiency Below Threshold
- P17BF — DSG Mechatronic Unit Pressure Fault
- P189C — DSG Clutch Actuator Pressure Deviation
- P2002 — Diesel Particulate Filter Efficiency Below Threshold
- P0299 — Turbocharger / Supercharger Underboost Condition
- P0011 — Camshaft Position Timing Over-Advanced
- P0700 — Transmission Control System Malfunction
- P0300 — Random / Multiple Cylinder Misfire Detected
- P0401 — EGR Flow Insufficient
- P0171 — Fuel System Too Lean (Bank 1)
- P0087 — Fuel Rail Pressure Too Low
- P0101 — MAF Sensor Circuit Range / Performance
- P0121 — Throttle Position Sensor Circuit Range / Performance
- U0101 — Lost Communication with Transmission Control Module
- U0001 — High Speed CAN Communication Bus
- C0035 — Left Front Wheel Speed Sensor Circuit
- B0001 — Driver Frontal Stage 1 Deployment Control
- P0234 — Turbocharger Overboost Condition
- P2463 — DPF Soot Accumulation
What Triggers a Check Engine Light?
Your car's ECU continuously monitors over 200 sensors. When any reading falls outside its programmed threshold for two consecutive drive cycles, it stores a fault code in memory and switches on the malfunction indicator lamp — the amber "check engine" light. The code doesn't name the broken part; it describes the circuit or system that is out of range. That's why professional diagnosis with a live-data scan is essential: a P0171 (fuel system lean) can be triggered by a vacuum leak, a clogged fuel injector, a failing MAF sensor, a faulty fuel pump, or a stuck EGR valve — each with a completely different repair cost.
A basic Bluetooth OBD dongle reads generic P0xxx codes from the engine module only. GarageNation's dealer-grade tools — ISTA (BMW), XENTRY (Mercedes), VCDS/ODIS (VW/Audi/Skoda), Techstream (Toyota/Lexus), GDS2 (Hyundai/Kia) — read all modules: gearbox, ABS, airbag, body control, climate, power steering and CAN bus. This is why we often find the root-cause fault in a secondary module that a basic scanner misses entirely.
How GarageNation Diagnoses Fault Codes
Our diagnostic workflow follows three steps. First, a full all-module scan captures every stored and pending fault code — including intermittent codes that cleared themselves. Second, live-data analysis: we monitor sensor readings in real time (injector pulse width, MAF flow, lambda voltage, boost pressure, transmission fluid temp, clutch slip %) to confirm whether the fault is active or historical. Third, component-level testing: we use oscilloscopes, fuel pressure gauges, smoke machines and compression testers to confirm the root cause before any part is ordered.
This process takes 60–90 minutes and costs ₹1,500–₹3,500 depending on diagnostic depth. The fee is waived when the repair is carried out with us. Free pickup and drop is available across Hyderabad — call +91 8106316369.
Frequently Asked Questions
- What is the most common fault code in Hyderabad?
- The most frequently diagnosed fault codes at GarageNation Hyderabad are P0741 (torque converter clutch slip — common in CVT and automatic gearboxes), P0420 (catalytic converter efficiency — often actually a failed O2 sensor), P17BF and P189C (DSG mechatronic pressure faults in VW/Audi/Skoda), P2002 (DPF soot overload in diesel cars), and P0299 (turbo underboost — usually a boost leak or failed actuator). These account for over 40% of all fault-code diagnoses we perform.
- Can I drive my car with a check engine light on?
- It depends on the fault. A flashing check engine light (indicating an active misfire — P0300–P0312) means stop driving immediately to avoid catalytic converter damage. A steady check engine light is less urgent but should be diagnosed within a few days. Fault codes like P17BF, P189C (DSG) or P2002 (DPF) in limp mode mean you should not drive at highway speeds. At GarageNation, we advise calling us on +91 8106316369 for a quick WhatsApp assessment before deciding whether to drive.
- How much does OBD fault code diagnosis cost in Hyderabad?
- At GarageNation Hyderabad, OBD-II fault code scanning and basic diagnosis costs ₹500–₹1,500 depending on the scan depth. A full advanced scan using dealer-grade tools (ISTA for BMW, XENTRY for Mercedes, VCDS/ODIS for VW/Audi/Skoda, Techstream for Toyota) costs ₹1,500–₹3,500 and covers all modules — not just engine. Diagnosis fees are waived when the repair is performed with us. Free pickup and drop is available across Hyderabad.
- What is the difference between P, B, C and U fault codes?
- OBD-II fault codes use a letter prefix to indicate the system: P (Powertrain) covers engine, gearbox, fuel, and emissions — the most common category. B (Body) covers airbag/SRS, HVAC, central locking, and comfort systems. C (Chassis) covers ABS, ESP/traction control, steering, and suspension. U (Network) covers CAN bus and module communication faults. The second digit indicates whether the code is generic (0) or manufacturer-specific (1). GarageNation's diagnostic tools read all four categories across all modules, not just engine codes from a basic OBD dongle.