Throttle Pedal Voltage Test Query

[ElectroMike]

Hello

Is it possible to get a sense check on whether I’m interpreting my voltage readings correctly?

I’m was thinking I have a throttle problem, but seems strange both my secondhand purchases have issues.

Specifications vs what I’m measuring:

Prius Throttle
P/n: 78120-47050
Sensor 1
Fully Released: 0.8V -- I get 0.821V
Fully Depressed: 3.6V -- I get 4.539V

Sensor 2
Fully Released: 1.6V-- I get 1.615V
Fully Depressed: 4.4V-- I get 4.638V


Lexus RX450
DENSO 78110-33011
Sensor 1
Fully Released: 0.8V -- I get 0.818V
Fully Depressed: 3.188V -- I get 3.826V

Sensor 2
Fully Released: 1.6V-- I get 1.633V
Fully Depressed: 3.988V-- I get 4.638V

Should the depressed voltage be matching the specifications, or just surpass them by a certain percentage?

[uhi22]

Just two ideas:
- Does the actual supply voltage match the specification (I guess 5V nominal)?
- Where does the "specification" come from? Is it the specification of the pedals full mechanical range, or is it the specification of the pedal mounted in the car, which may limit the mechanical range because the depressed pedal meets the floor?

[royhen99]

The "specifications" are typical values from a document explaining throttle position error code.
The best numbers I could find are the limits on a sensor tester in this post https://priuschat.com/threads/pedal-com ... se.230983/.

Sensor 1
0.4 - 1.4V Not depressed
3.1 - 4.6V Fully depressed
Sensor 2
1.0 - 2.2V Not depressed
3.9 - 5.0V Fully depressed

[ElectroMike]

Yeah, 5V. I used my bench power device to supply.
I got the specs from attached. Unless I'm reading them wrong.

I only ask, since I get an throttle12diff error with the prius pedal, and no torque request with other (although, this will probably end up being a separate post if the throttles are actually good to go!)

[royhen99]

potmin and potmax ( and pot2min, pot2max ) need setting correctly for each pedal to avoid above errors.

[ElectroMike]

Ah. Intersting. I'm currently using the RX450 pedal. But used the below values. Have I adjusted the values incorrectly? If this is more a zombieverter settings issue, I'll send a separate post re that instead if need be.

Prius
Potmin = 504 so using 515
Potmax = 2748 so using 2735
Pot2min = 984 so using 995
Pot2max = 2864 so using 2850


RX450
Potmin = 504 so using 515
Potmax = 2303 so using 2290
Pot2min = 988 so using 1000
Pot2max = 2808 so using 2790

[jrbe]

I'd suggest you don't get too stuck in matching the values called out for the pedals in oem references. OEM's will use resistors inline to the 5v to protect the ecu. This will skew readings from what you would see vs. direct 5v.

OI / zombie will have voltage dividers for 3.3v mcu's which will also skew the voltage some from what you'd see in the oem references.

So, dont try to calibrate the zombie or the OI board to a specific voltage, calibrate it to your actual pedal wired in place. Once calibrated, make sure you see a nice smooth throttle swing as the pedal is pressed.

[ElectroMike]

Ah, thanks. That's very helpful to know!