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Discussion Starter · #1 ·
One connection to the positive terminal of my Sienna’s battery needed its lug replaced requiring me to temporarily disconnect the battery. Since then, I can't get my 2004 Sienna LE to pass the “readiness monitors” so that I can get my state inspection, though it drives fine. (These are little tests that the car’s computer does in the background to verify that all systems are working properly and that the car is ready for emissions testing.) In the past, it never took much more than 100 miles of random driving to get all monitors to clear. This time, though, the EVAP and CAT monitors won't clear. A mechanic has verified this on his code reader as well. Also, we have both found that no codes or pending codes are set.

ILSienna256K reported on this site a very similar problem on a 2004 Sienna with the same 2 monitors, EVAP and CAT, stuck on “not ready”. Smog fail "Cat not ready"
But ILSienna256K reported that he was finally able to clear these monitors by following the drive patterns listed as “4” and “6” in this Toyota Technical Service Bulletin (TSB) so that his Sienna was ready for state emissions testing. I have very carefully followed drive pattern no. 6 to no avail. A note for drive pattern 6 in the TSB reads: “When the Readiness Monitor or DTC is set, this test is complete.” (“DTC” means Diagnostic Trouble Code.) This note is located immediately below the specified test period of 15 - 50 min. of idling. I interpret this information as meaning that A.) within 50 min, either the Toyota will clear the EVAP monitor OR B.) a DTC will be set. The other thing that this implies to me is if neither of these things happens, there is a problem with the Powertrain Control Module (PCM= same as an Engine Control Module, ECM, except that in Sienna it also controls the transmission). My tentative conclusion is that there is a problem with the PCM because if there were a bad sensor or bad connection, a code should be thrown. Does anyone out there have specific knowledge about this? Am I understanding the results of this test correctly? Does my PCM need to be replaced or re-flashed?

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Discussion Starter · #2 ·
One connection to the positive terminal of my Sienna’s battery needed its lug replaced requiring me to temporarily disconnect the battery. Since then, I can't get my 2004 Sienna LE to pass the “readiness monitors” so that I can get my state inspection, though it drives fine. (These are little tests that the car’s computer does in the background to verify that all systems are working properly and that the car is ready for emissions testing.) In the past, it never took much more than 100 miles of random driving to get all monitors to clear. This time, though, the EVAP and CAT monitors won't clear. A mechanic has verified this on his code reader as well. Also, we have both found that no codes or pending codes are set.

ILSienna256K reported on this site a very similar problem on a 2004 Sienna with the same 2 monitors, EVAP and CAT, stuck on “not ready”. Smog fail "Cat not ready"
But ILSienna256K reported that he was finally able to clear these monitors by following the drive patterns listed as “4” and “6” in this Toyota Technical Service Bulletin (TSB) so that his Sienna was ready for state emissions testing. I have very carefully followed drive pattern no. 6 to no avail. A note for drive pattern 6 in the TSB reads: “When the Readiness Monitor or DTC is set, this test is complete.” (“DTC” means Diagnostic Trouble Code.) This note is located immediately below the specified test period of 15 - 50 min. of idling. I interpret this information as meaning that A.) within 50 min, either the Toyota will clear the EVAP monitor OR B.) a DTC will be set. The other thing that this implies to me is if neither of these things happens, there is a problem with the Powertrain Control Module (PCM= same as an Engine Control Module, ECM, except that in Sienna it also controls the transmission). My tentative conclusion is that there is a problem with the PCM because if there were a bad sensor or bad connection, a code should be thrown. Does anyone out there have specific knowledge about this? Am I understanding the results of this test correctly? Does my PCM need to be replaced or re-flashed?

View attachment 60848
Sorry, I posted the wrong Drive Pattern. Here is the correct one:

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FWIW, I think only CA requires all readiness tests to have been run and post as clear/ok. NY and MA (the main non-CA nanny states) allow 1 not-ready monitor to pass. There are all sorts of criteria to get these things to run properly/fully. The ambient temp and the temp of the engine relative to ambient are critical for the evap test, but then the vehicle has to be started and warmed up to full operating temps. I've seen speculation that you have to keep the speeds between 10 and 45 mph, so it takes quite a while to get up to full operating temp. Once fully warm, it has to fully cool to ambient and stay there for 5 hours (IIRC). I believe that test to pass 3 times to set the monitor to OK.
 

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Discussion Starter · #4 ·
Hi Bill, Right, I think the mechanic who normally runs the smog test for me every year mentioned that here in PA we are allowed one monitor to not be ready, so I was trying to get this EVAP test done, as it doesn't require any driving because my smog test is expired. Also, as you can see, Toyota is extremely explicit about temperatures, etc. required to pass it. I did the procedure already once PERFECTLY, but with no result. It does say in the instructions that if you're at high altitude or in colder air, you could have to run the procedure twice. I suppose that if a pressure sensor either in the tank or for ambient air is failing (or temp sensor), the PCM may wrongly think I am on top of a mountain or something, so I am at this moment running the procedure again to see if I can clear the EVAP monitor or maybe even throw a code, which would give me a good clue as to where the problem is.

Thanks for thinking about this with me!
 

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Discussion Starter · #5 ·
Update: So, I carefully repeated "Drive Pattern 6" and let the Sienna idle in drive with the parking brake on for over 70 min, when a result was supposed to come in only 50 min. Again, this was based on the thinking above that some sensor is possibly reporting incorrect ambient temperature or 'altitude' (i.e. ambient air pressure), such that the PCM does not respond until the drive pattern is repeated. Well, I got the same result: absolutely nothing when I believe I should have either gotten a pass or a code. Is this cause to replace or re-flash the PCM?
 

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There are a couple of things that you should know about this process (speaking from MUCH experience).
1. If the battery is on it's last legs or is not FULLY charged before you attempt a drive cycle, the monitors may never all become ready. Same thing if the charging system is not functioning properly.
2. Performing a drive cycle (or just driving the van around) will not have ANY affect on making the EVAP system become ready. This test is done automatically in the middle of the night, when it is not being driven, after the engine has fully cooled down, and it repeats itself a couple of times over the course of several days before it proclaims that the EVAP system is ready. This test is the humming sound some people have heard coming from their van in the middle of the night. Once again, your battery's condition plays a big role in this.
If you can get just one of these two to flip it will pass inspection.
 

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Discussion Starter · #7 ·
Thanks Wag for weighing in. The battery is very strong having been replaced less than 2 years ago, but I will double check that it has a full charge. In my reading the web over weeks, I did get the impression that EVAP normally happens at night and I have heard something in my tank at an odd time before. Thanks for clearing that up.

It seems though that this "Drive Pattern 6" in the TSB does somehow trigger the EVAP to test. But it is not really a drive, just idling for a long time.
 

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Thanks Wag for weighing in. The battery is very strong having been replaced less than 2 years ago, but I will double check that it has a full charge. In my reading the web over weeks, I did get the impression that EVAP normally happens at night and I have heard something in my tank at an odd time before. Thanks for clearing that up.

It seems though that this "Drive Pattern 6" in the TSB does somehow trigger the EVAP to test. But it is not really a drive, just idling for a long time.
Your van will NEVER run an EVAP test when it is running, only after it has sat not running for at least 2 hours, after the engine temp drops below 95F, and the battery is at 12.6v or higher. We have problems with these here in Texas when it gets really hot in the summer. Sometimes the engine temperature never drops below 95F at night for a month or more. Furthermore, if the voltage drops too far during the test, the test will not complete. Additionally, the fuel tank needs to be between 1/2 and 3/4 full.
 

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you may have to drive it 200 to 400 miles. getting the exact procedure is almost impossible with traffic.

when you first start up, let it idle and get up to full temp. drive it on the highway and in the city.

Also VERY important to have more than half a tank of fuel at all times !!!


drive another 50 miles city and 50 miles highway. It will probably set all of the monitors. If not, just keep driving. You have to be patient. And obviously, DO NOT disconnect the battery or clear any codes with a scan tool. If you don't have a scan tool, now would be a good time to buy one.
 

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Your van will NEVER run an EVAP test when it is running, only after it has sat not running for at least 2 hours, after the engine temp drops below 95F, and the battery is at 12.6v or higher. We have problems with these here in Texas when it gets really hot in the summer. Sometimes the engine temperature never drops below 95F at night for a month or more. Furthermore, if the voltage drops too far during the test, the test will not complete. Additionally, the fuel tank needs to be between 1/2 and 3/4 full.
I thought it was 5 hours, but yeah. The complexity of this test is such that every State but CA allows 1 Not Ready test. The CAT test being not ready would suggest (maybe) that the O2 sensor (B1S2/B2S2) voltages are off. I'd probably check those. That test should clear as soon as your car gets even a little warm. It may be that your battery lug replacement wasn't as successful as you believed. If you're getting flaky/intermittent voltage or higher resistance than expected, your ECU(s) might actually think there's a bad battery in there. Alternately, if you replaced the lug due to extreme corrosion of the terminal, that may have creeped up the power/ground (whichever) wire and into the interior of the strands. This is a somewhat common occurrence, so it's something to consider as well.
 

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IIRC Calif allows one not ready but it can’t be EVAP.

Sixto
‘04 LE FWD 207K miles
Negative.
In CA, 2000 and newer model year vehicles will need all emission monitors in READY or COMPLETE status with the exception of the EVAP monitor. An incomplete evaporative monitor will not cause a smog check failure.
In other words, if the EVAP is ready and the CAT is not-ready, the vehicle will fail a CA smog check.
 

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Discussion Starter · #14 ·
you may have to drive it 200 to 400 miles. getting the exact procedure is almost impossible with traffic.

when you first start up, let it idle and get up to full temp. drive it on the highway and in the city.

Also VERY important to have more than half a tank of fuel at all times !!!


drive another 50 miles city and 50 miles highway. It will probably set all of the monitors. If not, just keep driving. You have to be patient. And obviously, DO NOT disconnect the battery or clear any codes with a scan tool. If you don't have a scan tool, now would be a good time to buy one.
[/QUO
2002 would be a Gen1 van. Not for your 3MZ-FE van, but from the later, 2GR-FE manual:

View attachment 60863
Yes, my 2004 Sienna has the 3MZ-FE engine, but there are several reasons to think that this test is the right one for my Sienna. The TSB indicates that it also applies to later models. In addition, ILSienna256K reported that it worked for his 2004 Sienna which he was also having trouble getting into the Ready state. Finally, I found this very same drive pattern online in the Toyota official repair manual for 2004 Lexus models with the 3MZ-FE engine. It is in Chapter 5 on Diagnostics of the SFI System which begs the question why no Readiness Monitor Drive Patterns are included in Chapter 5 of the Toyota Sienna Manual for 2005 model year available for download on SiennaChat.com?
 
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