M170 DBW TB Question (JRR)

Hey guys,

Making good headway configuring my M170 and have come up to the next item I need help with. I've got me pedal calibrated and correct TB chosen in the Servo Bank 1 Position dropdown. I can hear the TB moving, but at zero throttle its stuck at about 83%. If i press the pedal it does go back down and then progresses up as I press the pedal.

When I go down to Servo Bank 1 Control and Motor the Throttle Servo Bank 1 Motor Output is set to Bridge Output 1 (that's wired to the + side of the DBW TB). I've got HB2 hooked up to the negative side of the TB motor but I don't see anywhere that I can set this to permanent low side (if that's what's needed) to control the TB motor properly.

Any help is appreciated.

Sean

OUT_HB1 will be the Motor-, and OUT_HB2 will be Motor+. You can see this in the M1 Tune Menu: Help->Firmware Wiring where it shows Bridge Output 1.Positive and Bridge Output 2.Negative.

The Polarity of the Full Bridge will change depending on which direction it wants the motor to move.

As David said, swap the pins for HB1 and HB2.

David to the rescue!! Thanks for the pointer on the Help -> Firmware Wiring. I'm soaking up all this knowledge being very new and I greatly appreciate the help.

I'll get those pins swapped on my jumper harness easily enough next week after I get back from a long range charter fishing trip.

Hey guys,

Back from fishing and I swapped the pins for HB1 and HB2 and fired up the ECU today. I've got the Throttle Servo Calibration set to GM 1260 5109.1.0 (GM LS3 Gold Blade). I still had the problem with it showing as if it was at 80% throttle, but the TB was actually closed. So I swapped Throttle Servo Bank 1 Position Sensor Main Resource from AV Input 3 to AV Input 4 and changed the Tracking Resource from AV Input 4 to AV Input 3 and the TB seems to be working now. The Throttle Servo Bank 1 Diagnostic is "OK" through the whole travel of the pedal and TB and I can hear it opening and closing.

Now I've got the Throttle Servo Bank 1 Position (%) at 22.3 and the Throttle Servo Bank 1 Position Sensor Tracking (%) sitting at 18.8% with zero pedal. When I press the pedal just a bit it drops down to the lower percentage that would seem to match the pedal press percentage.

Is this normal or will I run into the next steps of my configuration that will address this?

That sounds normal. When the throttle body is not energized, the internal springs move it to the "limp home position", something like 22 % or so.

Awesome, thanks for confirming David!!

With the engine not running, the Throttle will go into Power Save, disabling the motor control, and thus the throttle plate moves to the neutral spring load position, this will be indicated by the Throttle Servo Bank x Diagnostic reporting Power Save. This should not occur when the engine is running, if it does then a fault has occurred that has caused the DBW control system to go into fault and enable the safety controls.

Awesome Stephen, thanks for the feedback. Haven't tried to fire it up yet, and I'm still working on transitioning my tune over from my AEM, so I am seeing exactly what you are describing and it makes perfect sense. I'm really enjoying learning the M1 platform, as steep a learning curve as it is, this platform and its member are invaluable in getting me going in the right direction.

Can't wait to fire my Factory Five Racing GTM back up!!