P0016 on a 60k mile car

[TheStig85]

Originally Posted by ermax

Is the engine cold or something? The target angle is 0.

It was idling. Again, I have no idea how to use TechStream. If anyone can chime in.

[steve99]

Originally Posted by EigenGuy

Final (hopefully) update:
Thank you Rusty for the guidance. I disassembled the timing chains again and figured out the issue. Apparently, the early 2013 model exhaust sprockets did not have the small triangle indicator stamped on the front to help align the drivers side sprockets during assembly. I was able to figure out the proper alignment and assembled everything were it needed to be. Once complete, I fired up the car and still had the same codes. I ordered and installed another (used) ECM and the codes have not returned after about 70 miles. To me, this confirms a ECM replacement is actually necessary even after solving the mechanical defect. For those considering doing this job yourself, it is not for the faint of heart. It required about 30 hours of work and significant studying time, not to mention a fair amount of dough for parts, fluids, and specialty tools.




My thought process here is this: force equals pressure times area. What if JDL's uel design is the perfect length to create a resonant PRESSURE wave FORCING the surface AREA of the exhaust valve open? This would stress the valve spring and therefore the variable valve timing components pushing the retention plate out of it's peened-in spot. Again, just a hypothesis based solely on a lot of reports of folks throwing these codes right after installing the UEL headers.

Originally Posted by alxtheoreo

Good hypothesis.

I wonder if a tune (dyno or OFT) has any impact on this failure? I know some local guys & some local shops reported this failure after they were tuned, or during the process of getting a dyno tune.

Most tunes will operate the vvt system either over a wider range or at a greater rate of change than the stock tune. Hemce a tune will put more demands on the vvt and will sgow up any latent issues

[rusty959]

Originally Posted by EigenGuy

Final (hopefully) update:
Thank you Rusty for the guidance. I disassembled the timing chains again and figured out the issue. Apparently, the early 2013 model exhaust sprockets did not have the small triangle indicator stamped on the front to help align the drivers side sprockets during assembly. I was able to figure out the proper alignment and assembled everything were it needed to be. Once complete, I fired up the car and still had the same codes. I ordered and installed another (used) ECM and the codes have not returned after about 70 miles. To me, this confirms a ECM replacement is actually necessary even after solving the mechanical defect. For those considering doing this job yourself, it is not for the faint of heart. It required about 30 hours of work and significant studying time, not to mention a fair amount of dough for parts, fluids, and specialty tools.




My thought process here is this: force equals pressure times area. What if JDL's uel design is the perfect length to create a resonant PRESSURE wave FORCING the surface AREA of the exhaust valve open? This would stress the valve spring and therefore the variable valve timing components pushing the retention plate out of it's peened-in spot. Again, just a hypothesis based solely on a lot of reports of folks throwing these codes right after installing the UEL headers.

That's odd, mine had the triangles stamped on all 4. Glad to see you got it back together.

Originally Posted by TheStig85

I still find this unbelievable... But I see other people confirming what you're saying on here: http://www.ft86club.com/forums/showt...=116309&page=3

But they're saying the ECM needs to be replaced as it can't unlearn values. Can anyone else chime in on this?

@Ultramaroon @rusty959 @steve99

Seems like most people, including myself, are willing to just spend the money for the ECU in order to get rid of the light immediately. It's already a small group of us willing to tackle this problem ourselves, even fewer are willing to wait a few thousand miles with no real picture of where the cuttoff is.

[Ultramaroon]

Originally Posted by TheStig85

It was idling. Again, I have no idea how to use TechStream. If anyone can chime in.

I'm in Cali this weekend. Will it be helpful if on next weekend I post up some screenshots of how I use it?

[TheStig85]

Originally Posted by Ultramaroon

I'm in Cali this weekend. Will it be helpful if on next weekend I post up some screenshots of how I use it?

Please do! I'll in the meantime try to figure out what I can.

Sent from my Pixel 2 XL using Tapatalk

[TheStig85]

Originally Posted by Ultramaroon

I recommend this $70 device and using its proprietary application that I demonstrated here. A $5 in-app purchase gets you the extended monitors. I'm not aware of any other real-time monitor but hope to eventually see it cracked for OpenPort II.

Watching the valve timing slew will give you peace of mind as you cross your fingers and wait for the ECU to re-learn whatever offset it needs. Maybe the offset is represented by one of the mystery values I am logging here. That would be cool.

I'm looking into the OBDLink app and see you can Purchase Extras. And there's the Toyota Enhanced Diagnostics. Guessing that's what I need? After that's purchased, do I just add Displays with the VVT PID?

[Ultramaroon]

Originally Posted by TheStig85

I'm looking into the OBDLink app and see you can Purchase Extras. And there's the Toyota Enhanced Diagnostics. Guessing that's what I need? After that's purchased, do I just add Displays with the VVT PID?

Yes. The function names are a bit cryptic. the main ones are target, which is the commanded angle, and change, which is the measured angle.

I have an idea about what the OCV Current and OCV Duty values mean but the others are a mystery. I hope that the Aim, and Hold Learn values have something to do with that slowly-learned table for which people have been replacing the ECU.


There is nothing sacred about how I laid out those gauges. Visual design is not my forte. :P

[TheStig85]

Originally Posted by Ultramaroon

Yes. The function names are a bit cryptic. the main ones are target, which is the commanded angle, and change, which is the measured angle.

I have an idea about what the OCV Current and OCV Duty values mean but the others are a mystery. I hope that the Aim, and Hold Learn values have something to do with that slowly-learned table for which people have been replacing the ECU.


There is nothing sacred about how I laid out those gauges. Visual design is not my forte. :P

Maybe I'm an idiot or something is wrong but only 4 of those gauges were moving.

Sent from my Nexus 7 using Tapatalk

[Ultramaroon]

Originally Posted by TheStig85

Maybe I'm an idiot or something is wrong but only 4 of those gauges were moving.

Not an idiot. The others have static non-zero values. I've discovered some related stuff in the manual. Still working to make sense of them. I also got some screenshots of Techstream in action. Will mark and upload ASAP. Tonight's our group's monthly karting meet.

[Ultramaroon]

Originally Posted by TheStig85

Maybe I'm an idiot or something is wrong but only 4 of those gauges were moving.

I didn't see the photo yesterday. I don't know why it didn't show up. Maybe I overlapped an edit?

I incorrectly assumed you were referring to the 4 target/actual groups.

Something is definitely wrong if you only saw 4 move. Is that screenshot a realistic image of the ones that move; 3 valve, and the tach?

That would mean:
1. your bank-1 intake is slewing properly,
2. your bank 1 exhaust is commanding a move but is not responding,
3. both bank-2 (intake and exhaust) servos are not doing anything.

Here are the screenshots I promised. I'll explain them and then hang back until you're ready for more. I'm baffled by the gauges. Maybe the bank opposite the faulty side goes to zero so the driver can limp home on 2 cylinders. Maybe I'm giving the engineers too much credit.

Here's the first way to make sure your fuel system is running in closed loop. I don't think it will let you manually slew the cams otherwise.





Here's a better screen to see the fuel mode and all the VVT params.





Here's how to get to the manual slew functions.





Here's a clip of me slewing bank-1 intake (p0016)

[ame]https://www.youtube.com/watch?v=RBqtg3Y3TD8[/ame]



Here's another potentially valuable screen. Not yet sure what it means.

[TheStig85]

Appreciate the response. Was busy this weekend so I didn't tackle this but out of curiosity I tried OBDLink on my cellphone with just Bank 2. Still, some of the gauges aren't moving. I'll try TechStream later unless you got some other theories.

Sent from my Pixel 2 XL using Tapatalk

[Ultramaroon]

Originally Posted by TheStig85

Appreciate the response. Was busy this weekend so I didn't tackle this but out of curiosity I tried OBDLink on my cellphone with just Bank 2. Still, some of the gauges aren't moving. I'll try TechStream later unless you got some other theories.

There's definitely something wrong. First thing to remember when you're troubleshooting using digital tools is that they overwhelmingly either work as designed, or fail completely. In other words, if it connects, you can be reasonably sure that the tool is working properly.

I suggest first looking for codes. Hopefully they will match up with what we saw with the monitors, that there is something wrong with bank-1 exhaust.

Let's also both study the relevant parts of the service manual. I'll review again tonight.

[TheStig85]

Originally Posted by Ultramaroon

There's definitely something wrong. First thing to remember when you're troubleshooting using digital tools is that they overwhelmingly either work as designed, or fail completely. In other words, if it connects, you can be reasonably sure that the tool is working properly.

I suggest first looking for codes. Hopefully they will match up with what we saw with the monitors, that there is something wrong with bank-1 exhaust.

Let's also both study the relevant parts of the service manual. I'll review again tonight.

Jumped in my car to leave work today. Figured I'd check the VVT readings again with the OBDLink. Didn't do this before, but I cleared the CEL this time around.

Voila! Like magic, the dials seem to be all working. Not sure if that's normal values or not. Maybe you can chime in.

Sent from my Pixel 2 XL using Tapatalk

[Ultramaroon]

Originally Posted by TheStig85

Jumped in my car to leave work today. Figured I'd check the VVT readings again with the OBDLink. Didn't do this before, but I cleared the CEL this time around.

Voila! Like magic, the dials seem to be all working. Not sure if that's normal values or not. Maybe you can chime in.

I'm going to go out on a limb here and guess that you haven't yet dug into the manual. Lay out your gauges to you can see the target and corresponding change gauges. Change angle must follow target angle.

In that screenshot they seem to be working ok.