How to log APP/ETC Voltages - REP Help - P59 - NA - SD Only

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07-06-2023
stroh

How to log APP/ETC Voltages - REP Help - P59 - NA - SD Only

Been battling reduced engine power issues in my 05 Silverado for almost a month now - has been a P1516 regularly, but have received P0068 and P2135 - and I can't find the voltages for the pedal and throttle body to watch/log to see what the issue could be. Pedal percentages haven't shown any issues, and usually cuts off at idle - so i don't think I'm hitting the upper airflow limit, and table is maxed anyway.

Thought I had it fixed as I hadn't had it pop up in the last week and a half, but cut off at highway speed last night with cruise engaged, which is a new failure mode.

I threw a bunch of parts at it while on the Hot Rod Power Tour and after to try and fix and keep going, but nothing has fixed it. TB, TAC module, x-link, pedal. Wiggling the harness, connectors will not make it happen - eight pin connector at throttle body has been verified good. Redid all the grounds, added grounds, no change.

Setup is a 102 bbk housing with a gold blade Camaro actuator, X-link. Got REP with this TB and the regular 87mm gm truck TB that was on the truck for a year. Actuator on current TB was on 90mm gm TB for six months before upgrade to 102. Cam is healthy solid roller 241/249 @ .050.

Anyway, I'd like to be able to log voltages for pedal and throttle body so I can properly diagnose it instead of throwing parts at it and hoping. Any other help would also be appreciated.

Thanks,
Ryan
07-07-2023
stroh

3 Attachment(s)

I created a new vehicle profile today and repolled for supported values (I tried not polling for values on a new profile too) and I don't get any pedal or throttle voltages.

These are the only channels I can select from - TPS voltage displays zero all the time.

Attachment 134256

When I go to graphs i can import these parameters, but anything that says voltage displays zero -

Attachment 134257

If I select supported channels this is all I get

Attachment 134258

Certainly this software/hardware should be capable of recording a basic input/output - pedal and throttle position voltage.

Thanks,
Ryan
07-18-2023
stroh

Anybody willing to offer any help before I swap ecus and os for a DBC setup?
07-18-2023
Alvin

1516 and 0068 are typically tuning issues on GEN 3.

The 2135 is the only one that indicates a bad throttle body to me.

Do you have a tune file posted?
07-18-2023
stroh

Older version posted here im mobile today can post latest later tonight

https://forum.hptuners.com/showthrea...998#post735998
07-18-2023
stroh

Oh and I lowered the threshold for P0068 since then, I'm pretty sure I was bumping the limit on vacuum at idle haven't gotten 68 since then only 1516
07-30-2023
stroh

2 Attachment(s)

Here's latest tune file from today. Couldn't get it to go into REP today (of course), but I did attach a log from when I did get it a while back.

HP Tuners support said "try scanning those pids" I can't figure out how to do that as I stated before polling for supported channels doesn't return any of the voltages I wanted to see.

P1516 could be an issue with the two voltages coming from throttle body - it would be nice to be able to log them to prove/disprove what the fault actually is - either the tune or mechanical/electrical.

Truck ran awesome with no REP for the first 500-600 miles with no changes to tune. Didn't change or add anything other than mileage - Valves haven't lost any adjustment and no vacuum leaks were verified today.

Ryan
07-30-2023
Hondaeater

Quote:

Originally Posted by stroh

Here's latest tune file from today. Couldn't get it to go into REP today (of course), but I did attach a log from when I did get it a while back.

HP Tuners support said "try scanning those pids" I can't figure out how to do that as I stated before polling for supported channels doesn't return any of the voltages I wanted to see.

P1516 could be an issue with the two voltages coming from throttle body - it would be nice to be able to log them to prove/disprove what the fault actually is - either the tune or mechanical/electrical.

Truck ran awesome with no REP for the first 500-600 miles with no changes to tune. Didn't change or add anything other than mileage - Valves haven't lost any adjustment and no vacuum leaks were verified today.

Ryan

Not sure why the Engine Diag MAF Hz fail set to 0hz when Dynamic high rpm is set to 4000, it is not set for MAF only OR VE only, and the DTC is set for NO MIL Light. Change p0101-p0103 to mil on 1st error. Or set these parameters correctly to run in Blended mode.

Set the Brake torque management in Torque management to disable 7800 enable rpm 7900.
In the TM> ETC limits, set that back to stock and see what happens. Your MAX Rotation for pedal in Airflow>ETC> does not match the Torque management settings for ETC limits.

Look back at your previous log, does the TPS rotation go higher than the Max pedal position table values per Pedal percent? It CAN because TPS is set to 100 percent on all but the 1st row in TM ETC limit, but did it when you look back over the log?
07-31-2023
Alvin

Quote:

Originally Posted by stroh

Here's latest tune file from today. Couldn't get it to go into REP today (of course), but I did attach a log from when I did get it a while back.

HP Tuners support said "try scanning those pids" I can't figure out how to do that as I stated before polling for supported channels doesn't return any of the voltages I wanted to see.

P1516 could be an issue with the two voltages coming from throttle body - it would be nice to be able to log them to prove/disprove what the fault actually is - either the tune or mechanical/electrical.

Truck ran awesome with no REP for the first 500-600 miles with no changes to tune. Didn't change or add anything other than mileage - Valves haven't lost any adjustment and no vacuum leaks were verified today.

Ryan

P1516 is in the tune and not a mechanical/electrical problem on GEN 3's. It comes from moving more airflow in a modded engine from stock.

set the enable for that code to 3 g/cyl
08-02-2023
Hondaeater

P1516 not p1514, setting the engine diag airflow up to 3 g/s for p1516??
May not work. Of course try it but....
Stroh I do recommend, since this is a TAC related issue p1516, you solve the conflict in the tables I mentioned before.
08-02-2023
Hondaeater

The fact you had no problem for 500 miles and now you do.... Did you change the way you drove, how much throttle you gave it now that it is broke in?
08-04-2023
stroh

3 Attachment(s)

Thanks for the help so far, but I'm still not getting anywhere

I can't find brake torque management in my TM tabs. I can't adjust limits for 1516 - only can set limits for 1514 which are already set to 4.0. Engine cuts off at idle when cylinder airmass is way under that limit anyways.

The only thing that changed since original tune was I went with a high volt alternator/battery and went a little tighter on valve adjustment. I've gotten REP on both alternators/batteries and with looser and tighter valve adjustments. Driving style did not change as in most cases it cuts off at idle - not sure how my driving style would change stalling at idle. First time I got REP it died in traffic at red light after waiting a minute or two for light to change (had driven from Atlanta to Columbia SC that day with no issues earlier). Has given REP one time while driving, at cruise speed but not logging because I thought it had been fixed at that point.

ETC limit is ~28% at 0 pedal and when it dies and I have recordings ETC is at 18-19%

Attachment 135243

Attachment 135244

And brake torque management is set to zero in system options:

Attachment 135245

Really would love to fix this thing (without spending any more money on parts because good lord this thing is eating my wallet alive) as it's a blast to drive. Would love to be able to run it down the track and see where I'm at. Made ~454 rwhp and it's a shame it just sits around waiting to be fixed. Still haven't completed the nitrous setup because this issue has me worried.

https://www.youtube.com/watch?v=jZ-EOl_QXOU

Thanks,
Ryan
08-04-2023
Alvin

I'm very sorry I meant 1514. Apologies.

Try 3. I used to max that table out and had issues on some OS's. 3g has never not worked for me.

I think 1516 is a wiring or throttle body issue. Have you gone through the service manual on that code?
08-04-2023
stroh

Quote:

Originally Posted by Alvin

I think 1516 is a wiring or throttle body issue. Have you gone through the service manual on that code?

We've come full circle now. I have followed it as far as I can go without measuring the voltages in the throttle body, which brings me back to the original question: How do I log throttle position voltages with this software? If I could log throttle position voltages it would let me know whether it's tune or mechanical/electrical.

DTC P1516
Circuit Description
The predicted throttle position (TP) is compared to the actual throttle position. The two values should be within a calibrated range of each other. Both the powertrain control module (PCM) and the throttle actuator control (TAC) module redundantly monitor the predicted and actual throttle position. This DTC sets if the PCM detects an out of range condition between the predicted and actual throttle position.

Conditions for Running the DTC
?DTC P1518 is not set.
?The ignition switch is in the crank or run position.
?The ignition voltage is more than 5.23 volts.
?The TAC system is not in the battery saver mode.
Conditions for Setting the DTC
?The TAC module detects that the predicted and the actual throttle positions are not within a calibrated range of each other.
?The PCM and the TAC cannot determine the throttle position.
?Both of the TP sensors are invalid.
?All of the above conditions are met for more than 1 second.
Action Taken When the DTC Sets
?The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
?The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
?The control module commands the TAC system to operate in the Reduced Engine Power mode.
?A message center or an indicator displays Reduced Engine Power.
?Under certain conditions the control module commands the engine OFF.
Conditions for Clearing the MIL/DTC
?The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
?A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
?A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
?Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
?Inspect the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
?Verify that the starting and charging systems are operating properly. Low system voltage can cause this DTC to set.
?When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing an individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
(from GM service)
08-04-2023
gtstorey

If you can't find them, they may not be there.
08-04-2023
stroh

Quote:

Originally Posted by gtstorey

If you can't find them, they may not be there.

It's bonkers to me that they wouldn't be as they are a basic input/output. Those voltages are on the CAN network for sure, just appears that somebody at HP tuners hasn't taken the time to translate them. Answer from HPtuners tech support was a nothingburger on this issue.

I guess the VCM Suite isn't the "flagship OBD II interface" like they say.

Anybody know of a cheap software that will let me log these voltages? I tried a couple different apps/hardware to no avail.
08-04-2023
wlwarnke

I fought Gen3 ETC issues for a bit on my swap. Found a bad connector at the TB, replaced it with a new connector and new pins from ICT. Seemed fixed for a few days, then again. Would only act up randomly and only while driving.

End of the day after lots of testing and cleaning grounds, depinning, measuring, etc....

The alternator wasn't getting a good ground. Measure voltage across the battery, then across the alternator. They should match!

Using a meter, positive on the battery positive, then use the meter negative and start poking around to everything that 'should' be grounded. Do this with the engine running. Anything that should be grounded, and is grounded properly, will read the same voltage as the battery.

Before, I wouldn't leave my neighborhood because i had to keep HPT connected so I could reset codes every minute or so.

Then I added a ground wire between the alternator bracket and the frame. Boom, fixed, not more issues.

Search my other threads for the full rundown, but that's it in a nutshell.
08-04-2023
stroh

Quote:

Originally Posted by wlwarnke

I fought Gen3 ETC issues for a bit on my swap. Found a bad connector at the TB, replaced it with a new connector and new pins from ICT. Seemed fixed for a few days, then again. Would only act up randomly and only while driving.

End of the day after lots of testing and cleaning grounds, depinning, measuring, etc....

The alternator wasn't getting a good ground. Measure voltage across the battery, then across the alternator. They should match!

Using a meter, positive on the battery positive, then use the meter negative and start poking around to everything that 'should' be grounded. Do this with the engine running. Anything that should be grounded, and is grounded properly, will read the same voltage as the battery.

Before, I wouldn't leave my neighborhood because i had to keep HPT connected so I could reset codes every minute or so.

Then I added a ground wire between the alternator bracket and the frame. Boom, fixed, not more issues.

Search my other threads for the full rundown, but that's it in a nutshell.

I wish it were that easy, alternator case grounded direct to frame, battery grounded to frame at same spot as well as engine block to frame and battery to frame at rear of truck. Redid all engine harness grounds, grounded TAC to body ran ground from that spot to engine.