I have a problem with a BMW M3 with an S65B40 engine. I can’t calibrate the DBWs (connected via CAN) because it gives me this error, but in reality when I press the pedals the TPS works, but with this error it doesn’t allow me to calibrate, any ideas?
It should not happen. We will fix this issue, thank you for the report. I’ve sent you DM.
Here are the logs. Basically, with idle active, it only corrects throttle 1 (throttle 2 remains stationary) and idle is a disaster. It seems that it sends the CAN opening signal only to throttle 1.
log idle no ok.emuprolog (185.1 KB)
PRIMA DI CAMBIARE STRATEGIA.emupro.zip (35.2 KB)
Hi @TonyEvo,
I checked your log. I’m pretty sure the problem is related to the bank 1 throttle itself, either mechanically or electronically, and not to the EMU PRO.
My guess is that there is some mechanical resistance causing rough throttle movement at low positions, or there may be an issue with the original BMW throttle electronics.
The reason I think this is because EMU PRO only sends the DBW target position over the CAN bus to the OEM BMW throttle controller. It does not control the throttle motor directly. Both banks receive exactly the same target position.
Bank 2 works correctly and smoothly, while bank 1 does not, which suggests that the problem is not related to the data sent by the EMU PRO.
Please check if the throttle on bank 1 moves freely at low throttle positions with the rod disconnected from the motor. If possible, also try connecting another set of throttles (even outside the engine) to confirm whether this particular unit is faulty.
That engine originally, in addition to 2 electric motors that control 8 throttle valves, also has an idle valve, which is no longer present on the car. Now I don’t quite understand a couple of things that happen. 1) during the DBW calibration, it makes me calibrate throttle 1 and throttle 2, while I calibrate the 1, the 2 also moves, the same for the 2 (maybe this is a minor problem). The 2 DBWs with the pedal seem to work without problems, they open and close, following the pedal. When I enable idle, the car starts, throttle 1 seems crazy, high idle and moves jerkily, throttle 2 is practically stopped. I then physically disconnected the shaft that connects the Dbw(1) physically to the throttle, turned it on, the car is perfect at 1000rpm, but if I try to raise the idle target (by 400rpm), dbw 2 still remains stationary, as if it were not being driven at all.
This is normal behavior for the S65.
For the S65 we had to adapt the standard DBW calibration procedure, even though the S65 setup is quite different from a regular single DBW system. That is why the software asks you to calibrate each throttle separately, just like with a standard DBW setup.
However, the DBW target is always sent to both throttles at the same time (as mentioned in my previous post), so both banks will move during the calibration process.
Please also note that the calibration procedure for the S65 only calibrates the throttle position sensors. It does not calibrate throttle motor behavior.
When you press the accelerator pedal, the throttles move out of the low TPS region (idle area). I suspect the problem happens only at very low throttle positions.
Please perform the following test:
- Make a backup of your current project.
- Disable the IDLE strategy completely.
- Set all values in the accelerator pedal translation table to 1.0.
- Start the engine and let it run for a few seconds.
- Then change all values in the table to 1.1 and again let the engine run for a few seconds.
- Repeat the same procedure for:
- 1.2
- After that, decrease the values step by step:
- 1.1
- 1.0
- 0.9
- 0.8
- 0.7
- 0.6
- 0.5
- After each change, let the engine run for a few seconds before changing to the next value.
- The engine may stall at lower values, which is OK.
- Save and send me the complete log from this experiment.
- After the test, restore your previous project.
Send me log please from this experiment
I have attached 3 logs.
Engine off open and closed is the log where with the engine off I open and close the throttles and the signal is perfectly consistent.
Engine on dbw connected is the current situation, dbw electrically and physically connected to the ITBs, the car has the defect I am complaining about, in which throttle 2 is fixed more or less at the target while throttle 1 has gone crazy.
The last log engine on dbw disconnected is the one in which the dbw on throttle 1 is physically disconnected from the lever that controls the ITBs of its bank (it is a V8), perfectly stable idle, but if I increase the idle target throttle 2 does not change because the dbw target does not change.
then I did a very important last test, I disassembled the DBW module and swapped between the 2 banks and I also swapped the TPS, so as to understand if the defect was behind the DBW module, but nothing, the defect (which practically oscillates in idle throttle 1) remained on the same side of the bank, so it did not follow the DBW module, it always remained on throttle 1. Another small note, when cranking I see that throttle 1 (always it) opens and closes (perhaps to help starting) which throttle 2 does not do. Sorry for the long message but it’s a problem that is driving me crazy.
(attachments)
engine off open e closed dbw.emuprolog (170 KB)
engine on dbw1 disconnected idle ok.emuprolog (424 KB)
engine on 2 dbw connected.emuprolog (851 KB)
We can see that both throttles work fine for a greater target values, but in a case of idle we need to watch the position when they are nearly closed. Please perform the mentioned experiment and post here the log.
Here I am, first of all, thank you for the support. I always reply a little late because the car is a bit far from me.
Once I fixed the calibration using the new software you provided, everything was perfect.
Then I had other problems with idle oscillation. I tried changing the DBW and TPS, but nothing. After a thorough wiring check, I saw that pin 8 on DBW had no ground. I opened the wiring and found the broken wire, which I fixed.
The idle speed improved but not perfect, and that was all I needed to do. I adjusted the throttle body closure (mechanically) and finally the car is perfect. I still haven’t properly mapped it (it’s a racing car, I need to go to the dyno).
P.S. There’s a small error in the wiring in the manual: Pin 6 of the DBW is mentioned twice, but in reality, the one that goes to pin 1 of the TPS goes to pin 9 of the DBW.
Good to know you have found the real problem and it works now.
Yes, you are right about the schematic. Thanks for the report, we will correct it soon.