Hitting max and min DC on Bosch E-throttle

[Yeahdoug]

Been chasing this issue for awhile. This on a turbo Can Am with Bosch e-throttle. It has an intermittent error that the DC will hit the max or min and then get a target error. I've got the generic Bosch e-throttle settings in it. Sometimes it can run 20 mins with no issues and sometimes it will run 2 mins and the throttle will lock up. Only happens when the engine is running. Won't do it just actuating the throttle as much as you want with the engine off. At first I suspected a mechanical issues, because when it errors out I'd have to push the blade back to its resting position by hand to get it working again. So we put a brand new throttle body on and it has the same issue. I've played with the PID, it tracks fine until the DC starts to go up and eventually locks up. I've tried different PWM freq... 10,000, 5,000 ,1,000 the same results.  Reset TPS/APS a bunch... I'm thinking it might be overheating and locking up or something?

I'm at the point where maybe the wiring is swapped on Aux 9/10? Is that even possible that it would run at all with that swapped?

I'll get some logs later tonight and add them. Added some screen shots of my setup. 

Anybody had something similar happen?

Thanks

[Vaughan]

Definitely need a log of it happening.

Swapping Aux 9&10 around just flips the direction it moves and this can be accounted for by changing the Aux 9 Active state, if it is working and moving correctly then your Aux 9/10 orientation is fine.

[Yeahdoug]

7 minutes ago, Vaughan said:

Definitely need a log of it happening.

Swapping Aux 9&10 around just flips the direction it moves and this can be accounted for by changing the Aux 9 Active state, if it is working and moving correctly then your Aux 9/10 orientation is fine.

Thank you, I figured it would swap directions. I'll be grabbing some logs from this weekend tonight. The car is on the other side of the country so it makes it even more of a challenge.

[Yeahdoug]

Sorry I was sent the whole log download. It's too big so I need to download just this section before I can post it.  This is the best I can do right now. You can see the DC starts out ok then drifts up and starts spiking max and losing control. It gets worse and worse before really losing control. It real feels like something is wrong with the throttlebody, but like I said this is a newer unit we swapped in. Could it be a driver issue? We've had this issue since day one when we built the car last year.

 

Some zoomed in shots. Start, middle, end. Not ideal but I wanted to post something tonight. Thanks

 

 

[Yeahdoug]

Another thing I thought of is this is out duning which means lots of throttle movement from bouncing around. Is this just working the throttle body too much and gets too hot. It puts more DC into it which makes the problem worse and basically thermally runs away? That throttle movement is very aggressive for just cruising along because of the bumps. I bet the stock ECU slows it down while the Link is trying hard to match the APS exactly.

 Should I try setting the clamps to like +/- 50% and see if that helps? 

[Adamw]

You can see in the last pic at 2:05 and 2:10 the ecu is sending 90% DC to the motor but the TP is sitting stationary at 10% which is about where the spring balance point is.  So - the motor is making no torque, that could be a bad connection in the wiring somewhere or something like the brushes losing contact with the commutator.  I have seen vibration cause the brushes to resonate and high RPM on some engines which causes the throttle to partially close, but yours occurs at relatively low RPM so I dont think it is a vibration issue.  It could be temperature related - causing the brush springs to go weak but I think it would need to be pretty extreme.  Does aux 9/10 supply show close to full battery voltage in the log?  

[Yeahdoug]

15 minutes ago, Adamw said:

You can see in the last pic at 2:05 and 2:10 the ecu is sending 90% DC to the motor but the TP is sitting stationary at 10% which is about where the spring balance point is.  So - the motor is making no torque, that could be a bad connection in the wiring somewhere or something like the brushes losing contact with the commutator.  I have seen vibration cause the brushes to resonate and high RPM on some engines which causes the throttle to partially close, but yours occurs at relatively low RPM so I dont think it is a vibration issue.  It could be temperature related - causing the brush springs to go weak but I think it would need to be pretty extreme.  Does aux 9/10 supply show close to full battery voltage in the log?  

Yes that is where the driver notices something wrong. You can see it starts to have small issues pretty early that build and get worse until it completely fails at 2:05. Wiring is stock except where it goes through a Motec adapter box (don’t ask lol) and pins into the ECU. I’ll go over all that again when I’m out west in a couple of weeks. 
 

I’ll take a look at the voltage when I have a second this morning.

Thanks Adam

[Yeahdoug]

Unfortunately I don't have Aux 9/10 voltage logged on the ECU, I'll add that. I went back and looked at some old PC logs and its looks like its around 13.6-13.8 volts and drops to 12.7-12.8 at high load. Doesn't look noisy or anything. 

The car also has trouble idling now because it looks like the throttle is sticking at idle. So it tries to move the throttle 0.1-0.2%, but nothing is happening. The DC goes up and up until it unsticks. Then it overshoots and the car dies or revs up. You can see in the data when its sticky and surging and when it's fine and idling great. It's completely stuck as of last night and the owner will have to push the blade down to free it up to even get it to idle and move the car off the trailer. 

I'm really down to double check wiring and try a different (3rd) throttle body. The problem is def getting worse and it feels like the TB is f'ed up. 

I hate E-throttles lol.

Thanks