Idle up?

[StevenS]

Andy - did you also wire in an extra resistor so the readings were 0.8v apart, and on the correct input?

Im thinking of using 2x adjustable regulators to achieve the input voltage I'm after

[lmichie]

My thoughts were to have the Hand controller come in at voltages that match the idle outut of the accellerator then drop out the accellerator so the two systems don't fight each other. One concern is that by the time an extra resistor is added to give the 0.8V offset at idle, the voltage ramps will be different so the gap will change as the two signal voltages are increased. Haven't got time to test the theory at the moment unfortunately.

[StevenS]

Good point
But if you use regulator and aim for a static idle increase instead of something variable it should make things simpler. Im aiming for a simple solution that most people here could easily mimic

[andy666]

Andy - did you also wire in an extra resistor so the readings were 0.8v apart, and on the correct input?

Im thinking of using 2x adjustable regulators to achieve the input voltage I'm after

yep. had the the two voltages set 0.8v apart and yes I had them hooked up to the correct sides of the pedal wiring.
Also the point of the dual gang potentiometer was so that the two signals increase evenly together. Yes checked when connected and appeared to be working correctly, but..... didn't work.

[StevenS]

I have a theory that if you (for example) feed a 2v signal into a line currently reading 1.5v (to increase idle) there is a difference that could cause the voltage to run back into the pedal. Whilst this could be fixed with a diode , a diode can drop the voltage by around .5volts which would cause even greater headaches.

If the feed from the POT was always higher than 1.6v AND a diode put in place it may solve the issue

[StevenS]

Im also thinking of using a transistor to boost the signal feed

[andy666]

I'll have another think about things on the weekend and see if i can come up with a solution.

A problem is that at full throttle the pedal doesn't read 5v is actually 3.2v and 4.1v on each pedal potentiometer. So what rpm will 2V give? Because you don't need to press full throttle to hit redline with no load on the engine and I wouldn't want a fast idle set at 4000rpm also if just fed into one side of the pedal it will cause a fault code.

Another problem I just thought of, is that the computer may be picking up some back feed from the potentiometer that shouldn't be there (because the pedal is non contact) and that may be causing the fault because it appears to be a short circuit.

[srluxy]

Are u guys sure its not a pulse witdth modulated digital signal. I work on heavy equipment and all the position
Sensors are a digital pmw signal. Therfore a variable resister wont work. You can check this on a multimeter using duty cycle and see if it varies when pressing the trottle.

[StevenS]

Its a typical hall effect sensor - no pulsed signal

[olcoolone]

Hall effect sensors can be either a pmw or a analog output.

Most pmw stuff in automotive are used to drive something and it's very rare for a pmw to be used on an input to an ecu.

The electronic throttle body may be pmw.

Easiest way is to use a dual channel scope and see what it's doing.



I don't know if this has be touched on before but have you thought about using the cruse control to tap up RPM..... we do this with heavy vehicles and at the moment we are doing it to the new Commodores for a special application.

The aftermarket Autron cruise control has a dealer test function that increaser the RPM whilst stationary for a few seconds.

[StevenS]

Ive seen that but i think it times out after 2 minutes

[StevenS]

How about increasing the feed voltage to 5.5v or there abouts. As long as the return voltage doesnt exceed 5v it should be fine

[olcoolone]

Ive seen that but i think it times out after 2 minutes

The timeout function is feature of the cruise control module it's self, might pay to speak to Autron and see if they can shed some light on the subject.

[olcoolone]

Steve I haven't read all you posts but what voltage input to the ECU from the peddle do you get at certain throttle positions.

I take the 0.8v differential is between the two sides (separate circuits)........

As for introducing a voltage, as long as you keep the voltage below that of the reference voltage given by the output of the ECU to the peddle then nothing will increase..... think of it as two 12 volt batteries in parallel to each other, you still only have 12 volts.

The only thing is if it is a pwm signal and you introduce a secondary voltage even if it is less then the reference voltage you will decrease the modulation width and in theory increase the voltage output.

A pmw supply can still show a reference voltage but the duty cycle will change (how many times it switches) as it is time over voltage...... some meters may not be able to read fast, a scope is ideal as you can time it.

First thing is to make sure it is not pwm

NOW I'm not being smart but before going into it to far and losing people by going over their heads..... do you have a good understanding of pwm.

[StevenS]

Ive played with pwm signals with my last car, a Toyota Aurion, when building a circuit to manipulate the speed sensors to "disable" the traction control

I strongly suspect the Hilux pedal using a non pulsed voltage signal from referencing the Aurions factory repair manual which seems to use an identical system

By increasing the voltage on the main feed lines I suspect it should up the voltage in turn on the return lines, as a flow on effect. This would happen by "cutting" the 5v ecu output and replacing it with a higher regulated voltage sourced from the battery - start with a 5.3v and go up or down as needed

[olcoolone]

I would not increase the voltage and cut the ECU output, this may bring up a fault code when the ECU watchdog finds there is no load on the output.

You may be better of to artificially introduce a higher voltage no greater then the reference voltage from the ECU output and use a 0.8v differential between the two circuits.

If you have 2 X 5v outputs from the ECU to the input of the peddle and the output from the peddle increaser the voltage to the input of the ECU...... so for example at idle you have 2 X 5v reference voltages into the peddle with with 2 x outputs from the peddle ..... 1 X output may be 1v and the other 1.8v...... if you were to drive the 2 X outputs from the peddle at say 1.4v and 2.2v you might increase the idle RPM base line.

Grab 2 X 7805 voltage regulators and trim their output to 1v and 1.8 volts and see what happens...... if you get smoke you know it doesn't work.

As long as you don't increase the voltage any more then the peddle input reference voltage.

"Off Topic But Important"......A sprint booster may work the same and increase the voltages on the 2 X outputs from the peddle by using a multiplication factor of say.... X1.15 or it may work on ramp up voltage where the multiplication increaser with voltage.


As for the Aurion I would say they would use the same set-up for their drive by wire as would most other Toyota's.

[andy666]

Can you compare an aurion to a hilux? Is the aurion a fly by wire wire or have a TPS on the throttle body?
If it was only a TPS and not a fly by wire then it would of only been a single sensor rather then running 2 sensors like the hilux becaus they don't have the same need for safety. If a TPS on a throttle body dies the car still runs on a map that uses the inputs from the MAF/MAP sensor and O2 in the exhaust to determine fuel ratios

You may be onto something with the pwm. I don't have a scope and I seriously doubt that a multimeter will be quick enough to sense this. Maybe the reason nobody has solved this mystery.

[StevenS]

Aurion is drive by wire, twin outputs on the pedal sensor. The actual operation is very clearly defined and it isnt pwm. Id say you had feedback as you didnt include a diode

[olcoolone]

Drive by wire still use a TPS as a feed back to the ECU, a TPS basically gives feed back to the ECU of how much the butterfly is open..... when a vehicle is controlled by drive by wire it uses a servo motor to control the butterfly that in turn is compared to a map in the ECU.

Nearly all servo motors use indexing to locate and know their position....... A TPS is a indexing sensor.

The way it works is..... the driver mechanically pushes down on the go pedal, the sensor in the go pedal converts a mechanical input to an electronic output that is converted by an ECU into a signal that the servo motor can understand telling the servo motor that's mechanically connected to the the butterfly in the air inlet what to do and by how much....... the TPS comes into play by sensing mechanically what position the butterfly is and when; converting the mechanical input back to an electronic output that in turn is feed back to an ECU that controls fuel, timing and spark by use of a map.

The go pedal would have very little to do with the mapping...... things that are needed to alter the controlling of fuel, timing and spark via a map are the TPS (throttle position sensor), MAF (mass air flow sensor), MAP (manifold Absolute Pressure sensor), Oxygen sensor, ambient air temp/ intake air temp sensor, speed sensor, crank angle sensor, transmission shift sensor and water temp sensor.

On later vehicles the traction and stability control may also have an active part to play... once again from a bunch of sensors and a map.

All these sensors do one thing only....... convert a mechanical or physical property into an electronic output that's able to be read by an ECU, the ECU gathers all this data and compares it to a preprogrammed map, if A B C D E F G are at this point this is what has to happen...... a sensor is just a converter.

Most EFI vehicles run failsafe systems that will operate a base level mapping, a TPS fault can do many things including cutting out the AC, cutting out the alternator, speed limiting, reducing power and in automatics play havoc with the shift points.

Modern EFI still isn't as smart as you may think.

[lmichie]

Trying to recap, what I was thinking and olcoolone was suggesting, if the "system" was switched in at 0.8V and 1.6V so they are "invisible" then switch out the tps so only the "system" is supplying signal. Then manipulate the "system" to supply idle up signals eg 1.2V and 2.0V so the gap remains constant. Then reverse to go back to accelerator control. Could be done with a multi position switch and some relays. to make sure the sequence works.