The “Egr Inc Obd2” code indicates a problem with your vehicle’s Exhaust Gas Recirculation (EGR) system. This system plays a crucial role in reducing harmful emissions. Understanding how the EGR system works and how to complete a drive cycle to trigger its diagnostic monitor is key to resolving this issue.
An OBD2 drive cycle allows your vehicle’s onboard computer to run a series of tests on various emission control systems, including the EGR. Successfully completing a drive cycle helps pinpoint the root cause of the “EGR Inc OBD2” code. Here’s a general drive cycle, often used by General Motors (GM), which may apply to your vehicle:
Cold Start: Begin with a cold engine. The coolant temperature should be below 122°F (50°C) and within 11°F (6°C) of the surrounding air temperature. Avoid turning the key on before the cold start, as this could prevent the oxygen sensor diagnostic from running. This step initiates tests for the O2 heater, Passive Air, and Purge “No Flow” systems.
Idle: Let the engine idle for 2.5 minutes with the air conditioner and rear defroster on. Maximizing electrical load enhances the effectiveness of this test. This stage helps evaluate the O2 heater, Passive Air, Purge “No Flow,” Misfire, and Fuel Trim diagnostics if closed loop is achieved.
Acceleration: Turn off all accessories and accelerate to 55 mph (88 km/h) using half throttle. This tests the Misfire, Fuel Trim, and Purge Flow functionalities.
Hold Steady Speed: Maintain a constant speed of 55 mph (88 km/h) for 3 minutes. This allows the system to assess the O2 response, air intrusion, EGR, Purge, Misfire, and Fuel Trim systems.
Deceleration: Release the accelerator and allow the vehicle to decelerate to 20 mph (32 km/h) without braking or shifting gears. This step focuses on the EGR, Purge, and Fuel Trim diagnostics.
Acceleration (Second): Accelerate to 55-60 mph (88-96 km/h) using 3/4 throttle. This repeats the diagnostics performed in the initial acceleration step.
Hold Steady Speed (Second): Maintain a consistent speed of 55 mph (88 km/h) for 5 minutes. This extended period allows for a comprehensive diagnosis of the catalytic converter, in addition to the tests performed in the previous hold steady speed step. Note that a marginal catalytic converter or a recently disconnected battery may require up to five complete drive cycles to accurately assess.
Deceleration (Second): Repeat the deceleration process as outlined in step 5. Again, avoid using brakes or clutch to allow a natural deceleration.
This drive cycle allows the OBD2 system to monitor the EGR system for proper function. If the “EGR Inc OBD2” code persists after completing this cycle, further diagnosis may be necessary using a professional OBD2 scan tool. Consult a qualified mechanic for accurate diagnosis and repair.
