GeekDIYMechanic – Readiness Monitors Overview GeekDIYMechanic – 2004 Hyundai Sonata Catalyst Readiness MonitorIn case you need to refresh your memory on Readiness Monitors, I suggest reading the following web page, Readiness Monitors.
Needing to renew his registration, he went to a SMOG station. He failed since not all of his Readiness Monitors completed. The tricky Catalyst Monitor was in a Not Complete state.
About 5 weeks ago, he replaced his battery, clearing all the Readiness Monitors. By the time he called me, he had already driven about two hundred miles. All of the Readiness Monitors completed except for the Catalyst Monitor.
After failing a smog test, the SMOG technician provided him with a Driving Cycle procedure. Unfortunately, my friend did not realize that Readiness Monitor conditions can be tricky to meet. You need to be as close to the prescribed Drive Cycle Procedure as possible. For example, he would not realize that the car needed to be completely cold at the start of the test, or that the speed had to be stay within a specific MPH range for a prescribed duration.
When I performed an OBDII Generic Readiness Monitor scan, the following list represents the state of the car's Readiness Monitors:
| Readiness Monitor | State |
|---|---|
| Misfire | Test Complete |
| Fuel System | Test Complete |
| Components | Test Complete |
| Catalyst | Not Complete |
| Evaporative System | Test Complete |
| O2 Sensor | Test Complete |
| O2 Sensor Heater | Test Complete |
| Components (18) | Test Complete |
| All Others | Not Supported |
Since he drove for over two hundred miles and tried to follow the drive cycle procedure, I looked at the following PIDs to see if perhaps there was a sensor issue causing the Catalyst Monitor to not start.
I didn't perform a full O2 Sensor diagnostics since both O2 related Readiness Monitors completed with no DTCs generated.
We combined what the SMOG technician gave him and what the SNAP ON Trouble Shooter proposed as the necessary Drive Cycle for all of the Readiness Monitors to complete. Here is what we did:
The outside air temperature was around 62°F, and the car had not been run in five or so hours. We executed the Drive Cycle at night in an effort to avoid traffic. We also used the Vehicle Speed PID to determine actual speed. This was important since he had different sized tires than specification causing his speedometer to not match the speed the PCM thought the car was moving.
For us, this allowed the Catalyst Readiness Monitor to complete.