2002 corolla,no RPM or tachometer.
Toyota dealer fixed the CheckEngineLight DTC P0446 by replacing vacumn switching valve and cleared the OBDII.
Now try to confirm the repairement by driving the specific cycle to make the EVAP monitor ready. Already tried 2 generic cycle but still not ready for EPVA. Got Toyota service bulletin for this year model and one procedure is 3000 rpm for 10 seconds.
How to do that without a RPM meter?
2002 corolla,no RPM or tachometer.
Sounds like you have a OBDII scanner. Some of them can monitor engine function including RPM. If you don’t, I’ve heard of some rented from some auto places, but I’m not sure about that.
Just drive it. If the problem is not solved, the code will return in short order. If it comes back, take the car back to the dealership and make them try again.
Did you check out this discussion on the EVAP problem?:
kit - I think you forgot the link. I wanted to click it!
Drive your car as normal for 2 days. That should give the monitor plenty of data to clear the ‘not-ready’ status. This has never failed on may of my repairs. Some have even cleared the status in one day.
Not everyone will hit all of the required criteria during “normal” driving where normal can vary dramatically between people and their local driving environment. Best way is to do what you’re doing and perform the required drive cycles as closely as possible.
If you’re going to perform the specific routines necessary to clear the code, then you need to understand as much as possible about all the conditions required of the test.
For instance, 3000 rpm for 10 seconds is probably not the entire set of criteria. First, achieving EXACTLY 3000 rpm for 10 seconds would be nearly impossible to do. The test will likely have a tolerance associated with the target rpm (+/-100 rpm for example). In fact, it might be more likely to be defined as AT LEAST 3000 rpm for 10 seconds. But I’m just guessing. Knowing that tolerance or the exact requirement will help you to determine if your test and measurement methods will be able to meet the test criteria.
Another test requirement could be that the vehicle must also be moving at some minimum speed in order for the test to be valid. In that case, if you simply revved the engine in park in your driveway, you would not meet all of the criteria. You’d be left wondering why it didn’t work. So, knowing the exact criteria is very important to know if you’ve met all of them or not.
If you know your final gear ratio and wheel size, you could determine a vehicle speed necessary for the specified rpm range. This will only work if the test has sufficient tolerance to allow for the errors inherent in this approach.
One method for getting the rpms high without the need for a high vehicle speed would be to select a lower transmission gear- say 2nd gear and enough throttle to achieve the desired engine rpm for the time specified.
Hi TwinTurbo, seems you understand the best of my situation. I post the full drive patterns below for your further suggestion:
Toyota tech service bulletin for corolla 2002 auto transmission, EVAP monitor:vacuum pressure moniotr/intrusive type.EVAP monitor readiness drive pattern:
Preconditions:MIL is off, Fuel level 1/2 to 3/4 full,altitue is 7800feet or less.ECT is between 40-95F, IAT is between 40-95F
1a:cold soak for 8 hours or until the differnece between IAT and ECT is less than 13F,Connect the OBDII scantool to DLC3 to check monitor status and preconditions.Release the pressure in the fuel tank by removing and then reinstalling the fuel tank cap.
2a:start the engine and allow it to idle until ECT is 167F or greater.
2b.Race the engine at 3000 rpm for approximately 10 seconds.
2c.Allow the engine to idle with the A/C ON for 15-50 minutes.
I am the layman for auto mechanic but with MSc degree can understand and find the infor online except the 3000rmp puzzle.
Appreciate any professional advise !!
In order to verify rpm at idle, you’ll need to either connect a diagnostic tachometer to the ignition system or use one of the OBDII diagnostic tools that has real time meters.
The first solution is the least attractive if you’re not going to be doing this kind of thing on a regular basis. It’s a temporary gauge that must be adapted to the ignition system (e.g. inductive pickup, coil over plug adapters etc) and temporarily “installed” while the test is being done. If you’re only needing this once, it’s a lot of expense for something that does only one thing.
There are many OBDII solutions out there. This is a tool that goes way beyond simply reading engine RPM and will pay for itself on the first MIL. There are enhanced tools that perform other functions that you may find useful. Here is one example- http://www.amazon.com/PLX-Kiwi-Calculator-OBDII-Scanner/dp/B001QJ7WSM
In order to read engine rpm, you’ll have to make an investment. It’s up to you what makes the most sense for your situation in terms of expense and usefulness.
Hi, TwinTurbo, So you think the 3000rpm for 10 seconds can be achieved at IDLE, just need a expensive meter to read it, don’t need to drive on freeway.
If so i will bring back to Toyota dealer and let the technician do it on-site if the EVAP monitor readiness issue will fail me for the coming NY state inspection next month.
For the past week i have driven the risky generic cycle for 3 times at midnight on freeway and EVAP monitor still show Incomplete today. I think i won’t try by myself anymore. Just wait it complete after natural drive for weeks.
But the strange thing is, while i had DTC last week after OBD reset, EVAP moniotr showed the pending DTC after 1st generic cycle and completed after 2nd generic cyle and matured the DTC and turned on the MIL. Do you think the EVAP monitor will complete differently with or without a diagnostic trouble code ? Thx !!!