Throttle position reading

[Qwimby1]

I'm running the Phantom electric supercharger on my 14 FRS, so I commonly have the OBD absolute throttle position reading showing. It recently went from standard 100% when floored, to 80.1 max. I can't figure out what caused that. I was concerned about mixture being too lean but it's 11 point something so I'm not concerned about that now. I don't know if the culprit could be the TPS or the throttle body itself. I talked to the guys that make my OBD reader and they said that it's telling me exactly what the ECU is telling it. Throttle body is clean and the butterfly opens wide. I'm not sure where to look next. I can pick up a lightly-used throttle body to try. I have a little more complication since I have a fused neck and can't turn my head much so I really can't work on the floor under the dash. I don't think I could change the TPS myself.

[FR-S2GT86]

Originally Posted by Qwimby1

I'm running the Phantom electric supercharger on my 14 FRS, so I commonly have the OBD absolute throttle position reading showing. It recently went from standard 100% when floored, to 80.1 max. I can't figure out what caused that. I was concerned about mixture being too lean but it's 11 point something so I'm not concerned about that now. I don't know if the culprit could be the TPS or the throttle body itself. I talked to the guys that make my OBD reader and they said that it's telling me exactly what the ECU is telling it. Throttle body is clean and the butterfly opens wide. I'm not sure where to look next. I can pick up a lightly-used throttle body to try. I have a little more complication since I have a fused neck and can't turn my head much so I really can't work on the floor under the dash. I don't think I could change the TPS myself.

Try the throttle position re-learn procedure. After disconnecting the negative battery terminal, wait about 30 minutes and then reconnect it. Then before starting the car:

1) Turn key to ON position, (or on a keyless model, press start button twice without stepping on the brake or the pushing in the clutch).

2) SLOWLY floor and fully release the accelerator pedal 10 times.

3) Turn key to off (or press start button one more time) to shut down.

Then start the car as usual. This should also be done anytime you reflash your ECU.

Let us know the result.

[Grady]

Throttle angle usually runs around 80, Accelerator angle should hit 100.

[Qwimby1]

Originally Posted by FR-S2GT86

Try the throttle position re-learn procedure. After disconnecting the negative battery terminal, wait about 30 minutes and then reconnect it. Then before starting the car:

1) Turn key to ON position, (or on a keyless model, press start button twice without stepping on the brake or the pushing in the clutch).

2) SLOWLY floor and fully release the accelerator pedal 10 times.

3) Turn key to off (or press start button one more time) to shut down.

Then start the car as usual. This should also be done anytime you reflash your ECU.

Let us know the result.

Very good input. I'll try that.

[Qwimby1]

Originally Posted by Grady

Throttle angle usually runs around 80, Accelerator angle should hit 100.

Reading all along has been Absolute Throttle Position per OBD reader. I think l I set my ESC activator switch using the OFT and could hook it up to see what it says. For those not familiar with the Phantom, there is a two-position switch that mounts under the throttle linkage. Initial boost is normally set at 60% throttle and full boost at 80%. But that's just a mechanical gizmo that has nothing to do with the electronics in the system.

[Qwimby1]

Originally Posted by FR-S2GT86

Try the throttle position re-learn procedure. After disconnecting the negative battery terminal, wait about 30 minutes and then reconnect it. Then before starting the car:

1) Turn key to ON position, (or on a keyless model, press start button twice without stepping on the brake or the pushing in the clutch).

2) SLOWLY floor and fully release the accelerator pedal 10 times.

3) Turn key to off (or press start button one more time) to shut down.

Then start the car as usual. This should also be done anytime you reflash your ECU.

Let us know the result.

Well I finally got around to trying that. Had to put in a new battery so it was a good time It didn't help. OBD still shows 80.4% max throttle is all I'm getting.

[Grady]

Originally Posted by Qwimby1

Well I finally got around to trying that. Had to put in a new battery so it was a good time It didn't help. OBD still shows 80.4% max throttle is all I'm getting.

That is a normal reading.

[Qwimby1]

Originally Posted by Grady

That is a normal reading.

Could be, but until recently it read 100% consistently. I monitor it regularly because the ESC switch activates at 60 and 80%.

[Grady]

Originally Posted by Qwimby1

Could be, but until recently it read 100% consistently. I monitor it regularly because the ESC switch activates at 60 and 80%.

I still think you are getting Throttle angle and accelerator angle crossed.

[Qwimby1]

Originally Posted by Grady

I still think you are getting Throttle angle and accelerator angle crossed.

I'm not sure I understand that. I get my absolute throttle position readings from my OBD, but just realized when I set the ESC switch to 60 and 80% throttle I used my OFT to measure. I think I'll get it out again and see what it tells me.