OBD Trouble Codes

NWACHUKWU AUTO CARE • DIAGNOSTIC CENTER

OBD-II Trouble Code Center

Find the meaning of diagnostic trouble codes, common symptoms, possible causes and practical diagnostic information for your vehicle.

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Popular Trouble Codes

P0300 Random/Multiple Cylinder Misfire Engine misfire diagnosis P0171 System Too Lean Fuel & air mixture problem P0420 Catalyst System Efficiency Catalytic converter diagnosis P0301 Cylinder 1 Misfire Individual cylinder fault P0335 Crankshaft Position Sensor Crank signal fault P0340 Camshaft Position Sensor Camshaft signal fault P0128 Coolant Temperature Thermostat / temperature issue P0455 EVAP System Leak Large EVAP leak detected

CODE CATEGORIES

Understand OBD-II Codes

P

Powertrain Codes

Engine, transmission and emissions-related faults.

B

Body Codes

Body, interior, airbag and comfort-system faults.

C

Chassis Codes

ABS, steering and chassis-related systems.

U

Network Codes

Communication and module network faults.

DIAGNOSTIC TIP

Don't replace parts just because a code appears.

A trouble code identifies a system or circuit that requires attention. Proper diagnosis should confirm the actual cause before replacing expensive components.

How to use an OBD-II trouble code

01

Read the Code

Use a suitable diagnostic scanner to retrieve the stored fault code.

02

Understand the System

Identify which vehicle system, sensor or circuit the code relates to.

03

Check Symptoms

Compare the code with the symptoms and vehicle operating conditions.

04

Diagnose Before Replacing

Perform the necessary electrical, mechanical or data-stream tests.