I have a Harley with fly by wire throttle (APP sensor - they call it TGS) The bike has a bad intermittent running issue and has 3 active codes P1510, P2122, P2138

P1510 is a limited performance mode indication{safety mode letting you know the bike is having fly by wire issues}.the p2122 is low voltage or open/broken wire in your fly by wire throttle sensor, and the p2138 is a throttle grip sensor correlation error.
I am not very familiar with this system, does anyone have any thoughts as to whether this looks correct? CAN'T UPLOAD FILE SO SEE DROPBOX LINK

https://www.dropbox.com/s/x2rpf7v5sm5npjj/TGS%20Voltage%20Test.psdata?dl=0

James can you give us any information on this system like a wiring diagram or a description and operation?

Trevor, The TGS has two potentiometers (designated as TGS1 & TGS2). The two TGS sensors work opposite of each other. TGS1 voltage ranges from 0.0-5.0 Volts, while TGS2 voltage ranges from 5.0-0.0 volts. The sum of the two TGS voltages should always measure approximately 5.0 volts.

The TGS1 and TGS2 sensors should never add to more than 5.13 Volts Direct Current (VDC) or less than 4.87 VDC . A sum of voltages out of this range should register a current P2135 code.

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Hi James,

I took a look here and added some math channels.

What jumps out at me is the deviation in TSG 2 in between 1.417 s and 1.671 s. Both math channels seem to register it too.

But during the following actuation it is not there, so I do not know if there is some sort of intermittent issue with TSG 2 maybe?

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Thanks for looking. I thought the same. Not being that familiar I'm just not sure how tolerant the system is of glitches before it is a problem.

Sam M. wrote on Oct 22^nd, 2022 at 1:50am:

Hi James, I took a look here and added some math channels. What jumps out at me is the deviation in TSG 2 in between 1.417 s and 1.671 s. Both math channels seem to register it too. But during the following actuation it is not there, so I do not know if there is some sort of intermittent issue with TSG 2 maybe?

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Logic that looks very interesting, did you build that calculator/program in excel? Thank you for sharing that.

Sam M. wrote on Oct 23^rd, 2022 at 2:43am:

Logic that looks very interesting, did you build that calculator/program in excel? Thank you for sharing that.

Yes I did

Understand the input for position % does not mean that a say 50% position on the throttle pedal results in 50% opening at the throttle.

That is subject to mapping.

But the excel application is good for either evaluating your scope voltage testing or making a custom probe set.

Logic wrote on Oct 23^rd, 2022 at 3:03am:

Understand the input for position % does not mean that a say 50% position on the throttle pedal results in 50% opening at the throttle. That is subject to mapping.

Excellent point for sure.

That is a helpful calculator to have, especially as it provides another way for data analysis.

It certainly looks like the 2 signals spend a lot of time outside the window of acceptability to me.

If the reference voltages and sensor grounds are clean and steady I would be examining that Twist Grip Sensor heavily.

For comparisons sake I went to look up an accelerator pedal position sensor correlation fault on a more familiar platform.
On a 2020 Chevy Impala 3.6 a P2138 code will set when APP Sensors 1&2 are not within calibrated range for 0.188 seconds.

I would imagine that a deviation of the Twist Grip Sensors for more than a similar period of time would result in a fault being recorded.

This could also be a good situation to apply some contact stabilant onto the pins of the connector and see if it has an effect.

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I appreciate all your comments and insight. I am going to replace the sensor.

James H wrote on Oct 24^th, 2022 at 5:59am:

I appreciate all your comments and insight. I am going to replace the sensor.

When you do, could you make sure to take a post-repair capture for comparison?

Yes

After some further investigation turned out to be a very intermittent 5 volt ref on the 1 leg from a pinched wire in the harness

James H wrote on Nov 22^nd, 2022 at 10:25am:

After some further investigation turned out to be a very intermittent 5 volt ref on the 1 leg from a pinched wire in the harness

Thank you for the follow-up.