MoTeC Global Forum

Hello!
Setting up an M130 with 4 throtte bodies and a Jenvey DBW actuator. Both the pedal and actuator have Penny & Giles sensors, that I have set up and read properly. PPS goes from 0-100% no problem, and TPS, when I move it by hand, goes 0-100% too.
Now, my problem is when I try to run the actuator. It just doesn't work. As soon as I touch the throttle, it goes into aim tracking fault. I'm a bit lost..., maybe I just spent too much time looking at the same screen. Ideas?

Assuming you are using GPA or GPR Packages....

Having just been through this with twin-throttle Nissan VQ35HR, I suggest you read the help in M1 Tune for Throttle Servo.

That describes the procedure for setting up the Main & Tracking sensors for the throttles. I found that I had to use the non-linear Throttle Servo Bank n Position Sensor Tracking Linearisation.

Be sure to make sure this table has 0=0 and 100=100 entries at the ends (and whatever you need in the middle). If you don't then it will default to using only the Main sensor and I think safety is compromised.

Most of what you want to do will be on the Initial Setup 2 Workbook, Throttle Servo Tab. I suggest you change the graph properties to include: Throttle Servo Bank 1 Position Sensor (Main, Tracking and Tracking Non-Linear) on one graph, and "Throttle Servo Bank 1 Position Sensor {Main, Tracking} Voltge" on another.

Another good Workbook for testing and identifying faults is Diagnostics, Throttle Servo Diagnostics tab.

Spend you time getting the main & tracking to match then you should avoid errors.

Hi,

Is this one of the Jenvey TB's that has two separate sensors? or is it using the single sensor with the Main and tracking in the same sensor?

We have found that with the two separate sensors there can be a difference in the amount of movement of the throttle shafts between the throttle bodies when the servo is operating, this means that the Main values follow the calculated values, but the Tracking values will have a lag in them, leading to the Tracking faults that you have experienced.

As David said, you can work around this by using the non linear Tracking Linearisation function, and mapping out the tracking values on this.

This Jenvey unit has just one sensor, with 2 outputs.
I went throtugh it again, I move the pedal by hand and both main and tracking move together, same values (=/- 0.5%), and when I do the same with the tps, I get same results, from 0-100 with same numbers. Throttle diagnostics and tps dagnostics, show ok all the time. BUT, when I connect the DBW unit, I get the tracking faut right away. Linkage moves freely, not sticking or anything.

Did you push the throttle blades to the zero position to set the zero. Sometimes the DBW mechanism will have a spring loaded rest postion that is like 3% or so. Could you have the DBW motor polarity backwards? So it got the tracking fault because the Throttle Position went the "wrong way". Been there, done that..

Yep, throttle blades pushed to 0, and checked polarity (been there too...). I even tried disconnecting the motor from the linkage (tps attached to the motor), to make sure there was no problem with the shafts or anything. It will not move. But, when I reset the computer, it does the full travel.

Hi Yori,

Do you have any logging of this? I would be interested in looking at it if you do.

Have you set the Throttle Servo Bank 1 Position Default to be the Main Position when the motor is not active?

What is the Throttle Servo Dead Band?

Do the Servo PID settings look reasonable?

Have you been able to use the Throttle Test. Try static test, then change the Throttle Test Aim.

I haven't been able to run the test, steps nor steady. I'm sending a log. What gets me everytime is diagnostic status on both sensors is OK, but the thing won't move. Any input will be greatly appreciated

Unfortunately the standard diagnostic logging doesn't have nearly enough logging information to debug DBW throttles. On my recent project, we had to enable level 1 logging then logged all the Throttle Servo * channels at 50 hz. However your log file does include your M1 config, so that is helpful...

Looking at your M1 config, I am surprised by a couple of things:

1 - You use Absolute Voltage reference for the Throttle Servo Bank 1 Position Sensor Main and Tracking. Normally there is a 5V reference supplied by the ECU, and you want to specify which 5V supply you used. The output from the sensor is normally ratiometric, not absolute.

2. Your Position Sensor Main voltage goes from high to low and your tracking voltage goes from low to high. This shouldn't matter, but typically these are the other way (tracking his high to low). If these are wired to the throttle body backwards, perhaps you have the motor polarity backwards, too.

Earlier you said the throttles do the full travel when you reset... I seem to remember that the throttles only go to the zero position to correct the offset (I don't have a DBW car handy to confirm) -- if you had the motor polarity wired backwards they would move the opposite way.

Please try reversing the Bridge polarity and see if that makes a difference.