We understand your Acura TL is having difficulty getting certain emission monitors to complete (become Ready). Emission monitors are internal self-tests which the engine control computer (ECU) performs in order to verify specific emissions systems, such as the EGR system, EVAP system, oxygen sensors and Catalyst, are functioning properly. If any one monitor is incomplete, not including the EVAP monitor, your Acura will not be able to pass the smog test. The EVAP monitor is the only monitor allowed to remain incomplete and the vehicle still pass the smog check because of the difficulty of getting this particular monitor to complete.
The emission monitors are tested and set to Complete or Ready status while your Acura is being normally operated. However, due to different driving habits, the criteria required to run a monitor may not always be met. Following the Acura TL drive cycle below should allow all emission monitors to complete. The drive cycle must be followed accurately. Take extra caution when performing the drive cycle on public roadways. Perform the drive cycle at your own risk. Perform the drive cycle safely and obey all traffic laws.
We're going to recommend that you follow the drive cycle below at least twice, and if after that, your Acura still has not completed all the emission monitors required to pass the smog inspection, seek the assistance of a smog check repair station which will be able to perform the drive cycle on a dynamometer and be utilizing specialized OBD II drive cycle readiness tools/scanner/computer.
Usually 200-300 miles of driving, and over the course of a few days and in both city and highway traffic conditions, is enough to get the drive cycle complete. Due to individual vehicle owner driving patterns however, sometimes the criteria required to get a particular monitor to initiate and/or become ready is not met. In such instances, it is required that a specific drive cycle pattern which is designed for the Acura TL be followed.
How to Perform an Acura TL Drive Cycle
These monitoring systems include the catalytic converter, EVAP system, oxygen sensor, oxygen sensor heater, EGR system, secondary AIR system, and misfire monitor.
- Ensure the Check Engine Light is not on.
- Gas tank fuel level must be between 15% and 85% during the drive cycle.
- Engine temperature requirement is between 68 and 86 degrees F prior to drive cycle start.
Note: The secondary air injection monitor which checks for the performance of the air injection system and air injection pump requires the monitor run during a cold (engine) start. Once the engine warms up, the monitor is done checking the air injection pump and will continue on checking the performance of the remainder of the AIR injection system. With that said, it's not the number of miles driven which resets the air injection monitor, rather the number of cold starts required to get all the other parameters required for the air injection monitor to to run. Starting the engine after the vehicle has sat for at least 8 hours in normal weather conditions would be considered a "Cold Start". Since the air injection monitor takes into effect ambient air temperature, it is best to perform a cold start on a morning.
START HERE - The Drive Trace:
1. MIL (malfunction indicator lamp) must be off
2. Cold start (Best to start in the morning after the vehicle has sat overnight)
3. 1/4 to 3/4 fuel in gas tank. Ensure your Acura is not running empty or full of fuel.
1. Without depressing the accelerator pedal, start the engine and idle for 20 seconds.
2. Keep the transmission in Park. Increase the engine speed to 2,000 rpm and hold until engine temperature gauge rises to 1/4 of the scale. Approximately 3 minutes of idle time should accomplish this.
3. Begin driving. Increase speed to 50-60 mph as soon as safe and possible and maintain speed for at least 20 minutes. This step should be performed on the highway and with the transmission in Drive. Cruise control should not be enabled at any time.
4. Drive an additional 90 seconds without moving the accelerator pedal at all. You may vary your vehicle speed vary slightly; no greater than 3 mph. If it is not possible to maintain steady speed for 90 seconds, drive for at least 30 seconds, then repeat 30 second steady speedy intervals, twice (for a total of 90 seconds). The goal is, at some point of highway driving, to not move the accelerator pedal for 90 seconds.
5. Exit highway and reduce speed to city/suburban traffic. Drive for at least 10 minutes.
6. When possible, allow vehicle to coast for 10 seconds without depressing the accelerator or brake pedal.
Drive Cycle Complete. If possible perform the drive cycle twice and using a scan tool check for emission monitor readiness.