oBD2 not ready

My 2009 will not go READY for the cat and O2 tests. No check engine lite, no codes or pending codes. Have completed many driving cycles since battery replacement !

Ran a scan and several emissions tests 'Not Supported'?? Also, the cat temp bank 1 sensor 1 (pre cat sensor) puts out a bad temp at startup? But then it starts working when you drive the vehicle a while (least that is what scan tool says)?
The latter may be why no 'check engine lite'? Have checked all fuses, wiring looks good and car runs great... A solid code for a bad cat or O2 sensor is one thing I can deal with, but no codes and not emissions ready has got me baffled!
Something screwy with this ECU maybe or cat- o2 sensor is boarder line but truck only has 35k miles on it. Lastly, did read all the input on driving cycles, including the Toyota readiness monitor drive patterns doc.
Any thoughts? Thanks

 

Typically in many cases in order for certain OBD2 and emissions tests to be performed, then vehicle must have a "cold" start. Usually a cold start is when the engine coolant temperature drops to 88Deg F. Living there in phoenix, it may not be POSSIBLE overnight for the engine to cool down that far. Just my thoughts.

 

no all ready codes are possible to set, ignore those that say Not Supported. system will go ready anyway...after time....

how many miles/tanks since last reset ?

I have tried to follow printed readiness patterns myself and can never intentionally complete them no matter how hard I try. What does work is driving around on highway and around town for 40 to 200 miles, forget I am trying to set it, and it will set. Once, it took two tanks and a week !

To what BamaToy replied... he might be correct

there are two parts to cold soak

a) the vehicle cold soak for 8 hours or until the difference between IAT (Intake Air) and ECT (Coolant Temp) is less than 13F (7C).

b) However, if the engine bay does not ever cool below 95deg F it will not pattern: ECT (Coolant Temp) is between 40F and 95F (4.4C – 35C).

 

One other thing to possibly give thought to is that sometimes ECU's can go "bad".
This doesn't mean that it won't function or that the engine won't run but it may and can cause strange symptoms that just don't make sense.

Good luck with this problem. I hope you or the shop that works on your truck finds the issue quickly and inexpensively.

 

Thanks for the input! Also thought about Phoenix and a cold start. Truck was stored on east coast (NC) for a year and a half, and a battery replaced last month before I picked it up and drove it to Phx. Tried emissions in VA before leaving and got the first 'not,ready' and expected that as son did not pay for a trickle charge while in storage.

However, 2400 miles later, mostly highway driving, expected to, pass here in AZ. After the third NR, took it into toyota for recalls, one of which required disconnecting battery. I did ask rep about NR status and all he said was drive it some more.

So after another week or so of driving looked up,the cycle req's even though they were written in 2002 thought that was it? However another week, 100 miles still no go

Borrowed a scanner and that was when I found the odd o2 temp reading and of course, not ready...if it's still not ready when son arrives from overseas, will let him deal with it in Colorado (least the cold temp req should be met).
Personally think it will have to go through some real good diagnostics with a good toyota tech.
Thanks again
Rick

 

you drove 2400 and it has not reset ? i am gonna say something ECU related then...might need a software update. just about no way can you avoid the pattern 2400 miles unless you truly stay on highway and never drive around town whatsoever, and never sleep

toyota doesn't update the driving pattern much, and one pattern applies to almost all vehicles....but there are old TSB's on it

 

That's sort of what I been thinking too (as did another comment). I've done some performance tuning years ago and know you can interrogate all of the I/O on a OBD2 system. But even if the ECU itself passes it's own health check, e.g., no codes... still doesn't mean one of the components isn't missing a 'bit'? Not a typical failure mode, but does happen occasionally.

Guess will have to wait and see? Son is going to have to do some talking with Toyota if it is a ECU with only 35k on it. Thanks

 

I Know I am right! 20+ years of dealing with OBD1 and OBD2 diagnostics. You kinda get used to what has to be done for certain tests to even run, much less pass. I have seen some codes go months before testing because the driver's normal driving pattern would never enable it.

I do agree with 127 that with all of THAT driving, to never have ran the test seems unusual. The thing that would need to be looked at is in the data parameters, it should show "mileage since last test". Your vehicle, depending on the code being tested, will run many many times over. It could be possible that when you drove the first time on the long run that it DID run and pass, but when you turned the engine off, and then restarted, it would recycle to perform the next test.

When you first start your vehicle it typically will set itself up to perform all of the tests on the list. Some will be tested and passed immediately (crank sensor, can sensor, etc) others will have to fall within the parameters of the pre-test before it will run the test. I am thinking that it may be possible that the test HAS been run before, and passed, but when you turn the engine OFF, it will reset. What you need to do is start the truck up and go through a standard emissions test drive. AFTER that drive, THEN check the parameters BEFORE you turn off the key. For example the P0420 test you would have to do the following chart:



As you can see, if at ANY time during that drive, you fail to maintain about 37mph for 10 solid minutes, or between 47 and 63 mph for 10 MORE solid minutes, while maintaining a reasonably constant engine load, your P0420 code will remain showing "not ready" because you haven't completed the drive cycle. Just like 127 points out, it seems the harder you TRY to make it go into testing, the more it resists. However for situations like me, where I may drive around town and NEVER hit the highway for 2 or 3 weeks, My P0420 test won't perform but maybe 1 time a month.

 

Man; modern vehicles are really complicated.
I like reading stuff like this, but, while I can work on my Land Cruiser, this stuff is right over my head.

 

Had this on my Sienna; had a coil go bad so off to dealer; while you're there do my emissions and Va. inspection. They dosconnected the battery to do the work. Failed emissions on 'not ready' so had to drive it a month and come back and it passed. Fortunately i didnt' need my plates renewed too soon.
All of this is to make sure a battery disconnect doesn't alter the codes on an otherwise sick emissions system to sneak it through....

 

Yep, battery disconnects when emissions due not good! I hope Bamba is right on the cycles! Definitely the logical conclusion and I know it's hard to do the requirements here in Az.
Also being an old computer guy, we seem to always dive into the low level electronic stuff and sometimes forget 'to see the forrest thru the trees'!

Will post again when successful, taco will be here another month or so before going up north.
Thanks rick

 

Stranger things have happened. I had an '86 Oldsmobile Calias Supreme some years ago and it was hesitating and running sluggish, but no engine light. I suspected the O2 or TPS sensor but was hesitant to just throw parts at it, plus couldn't afford to. 2 months later it finally tripped the light and told me the 02 sensor was garbage.

I forget what system it was, I don't even think OBD1..

 

This may be the issue as during the summer it won't drop below 90 for about a month or so. We are just hitting the hot parts of summer here in Phx.

 

Dumb question, but is it possible to garage it overnight..and it wouldn't hurt to have a fan or AC unit in the garage

 

Good news guys! After forgetting about cycles an just putting another 200 miles on it locally, the scan this AM said READY!!! Got to emissions and passed like it should.

So while I may have been a bit Leary, the advise to wait it out was right all along.
Thanks rick