Facing a smog check failure can be frustrating, especially when you’re told your car’s monitors are “not ready.” This often happens after a car battery replacement or a service that resets your car’s computer (ECU). Like many others, I found myself in this situation after a dealership service campaign reset my ECU, leading to a smog check failure due to incomplete Catalyst and Evap monitors. While the Evap monitor isn’t always necessary to pass, the Catalyst monitor is crucial. Long drives didn’t solve the problem, so I turned to a practical solution: the Autel Autolink Al319 Fault Diagnostics Code Scan Tool.
Initially, I was advised to take my car for an extended drive, and I did just that, driving over 200 miles in the Tujunga area. Despite the long distance, the monitors remained incomplete. Frustrated and needing to pass smog, I decided to take matters into my own hands. After finding limited options at local auto parts stores, I purchased the Autel AutoLink AL319 OBD2 Scanner from Walmart. This tool proved to be essential in completing the necessary drive cycle and getting my car ready for a successful smog test.
The key to completing a drive cycle isn’t just about mileage; it’s about following a specific driving pattern that allows your car’s onboard diagnostic system to run and complete its self-tests. I found a detailed OBD2 drive cycle guide online, which outlined a condition-based process rather than just distance-based driving. This guide emphasized precise steps to activate the monitors and set them to a “ready” status.
The drive cycle procedure I followed, and which you can replicate, is as follows. It’s recommended to perform this process twice over consecutive days for the best results and to adhere to the instructions precisely:
OBD2 Drive Cycle Procedure:
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Initial Setup:
- Switch the ignition ON for 30 seconds without starting the engine.
- Use the Autel AL319 to check for any Diagnostic Trouble Codes (DTCs) and address them if necessary.
- Ensure the engine coolant temperature is below 140°F (60°C) before starting.
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Engine Start and Idle:
- Start the engine.
- Let the engine idle for 2 minutes.
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Acceleration Phases:
- Perform 2 light accelerations from 0 to 35 mph with gentle pedal pressure.
- Perform 2 medium accelerations from 0 to 45 mph with moderate pedal pressure.
- Perform 2 hard accelerations from 0 to 55 mph with heavy pedal pressure.
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Cruise Speeds:
- Cruise at 60 mph for 5 minutes.
- Cruise at 50 mph for 5 minutes.
- Cruise at 35 mph for 5 minutes, ensuring not to drop below this speed. Maintain a steady speed, avoiding excessive throttle or lifting off the throttle completely.
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Final Idle and Check:
- Let the engine idle for 2 minutes.
- Use the Autel AL319 fault diagnostics code scan tool again to check for DTCs and monitor status.
Important Notes for Drive Cycle Success:
- Do Not Interrupt: Avoid turning off the car in the middle of the drive cycle.
- Air Conditioning Off: Do not use the air conditioner during the drive cycle.
For convenience, I kept the Autel AL319 OBD2 scanner plugged in throughout the second attempt at the drive cycle. With a helper to monitor time, I executed each step, adapting slightly to real-world driving conditions. While maintaining exact speeds and accelerations wasn’t always possible due to traffic, staying close to the guidelines and completing all phases proved effective. The 60 mph and 50 mph cruises were manageable, but the 35 mph cruise required finding a suitable straight road to maintain a constant speed. During the 35 mph cruise, after about 3 minutes, the Catalyst monitor finally completed – indicated by a distinct beep from the Autel AutoLink AL319.
Although the Evap monitor did not complete in my case, it wasn’t required for my vehicle to pass smog. The Autel AL319 continuously beeps as it monitors the system, which can be a bit noisy, but it provides real-time feedback on the drive cycle progress. Remarkably, the drive cycle was completed on the first day of trying the detailed procedure, eliminating the need for a second attempt.
In conclusion, the Autel AutoLink AL319 OBD2 scan tool was instrumental in diagnosing the readiness monitor issue and facilitating the completion of the drive cycle. For anyone facing similar smog check problems due to incomplete monitors after an ECU reset, the Autel AL319 and a precise drive cycle procedure can be a cost-effective and efficient solution, saving time and further frustration.
