Link2ThePast Posted November 27, 2022 Report Share Posted November 27, 2022 Hi guys, looking for some guidance and possibly a solution. I've finished adapting a BMW S54 throttle actuator to my 2zz and am using it to drive 4age blacktop throttles. The throttles are unmodified and have their return springs intact. The same can be said with the actuator. Currently when trying to calibrate the TPS, the system starts to go through the process, completes the first closed/opened sweep of the throttle plate. At the end, the test says that it's closing the TB again but doesn't, and it give the message that H-Bridge polarity is reversed. This happens regardless if I change the output state to high or low for aux9. I was previously using the same wiring setup to drive a stock E-throttle so I know the wiring isn't the issue on the ECU side. I've switched the sensor pins on the TPS plug because it was originally opening the throttle when the calibration was closing it and that fixed that error but I am stuck at what to do. Any help would be greatly appreciated I've scoured the internet trying to figure out what the issue is here and only came across this post which describes exactly what I am experiencing: https://forums.linkecu.com/topic/13879-tps-calibration-issues/ I just made a log and will be going through that in the mean time. Here is the link for the Log and Cal. Log is dated for todays date in PST and the cal is named "itb e throttle" https://drive.google.com/drive/folders/1CiPYR6NEtvaxv4rIjn_7SoY6Vur5pgp1?usp=sharing Quote Link to comment Share on other sites More sharing options...
Adamw Posted November 27, 2022 Report Share Posted November 27, 2022 This will happen if the return spring is not strong enough to close the throttle on its own when the ecu does a direction test by turning off power to the motor when blade is fully open. On a conventional throttle if the ecu turns off power after the calibration and sees the the TPS move significantly due to the spring (towards closed) then it knows it was working in the correct direction. If it doesnt move significantly from what it believes was the open position then it considers it is probably set up backwards and was already closed. In your case it may just be there is not enough spring to naturally return the motor and blades to nearly closed. Just do a manual calibration instead, turn off E-throttle relay, move throttle to full open with fingers, note down the TPS main and sub voltages. The push blades fully closed and note down closed voltages. Then manually type the open/closed voltages into the TPS settings. Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted November 28, 2022 Author Report Share Posted November 28, 2022 Thanks for responding Adam. I was doing some testing in the meantime and I came to the same conclusion. Kinda weird that it just shuts it off on the final step instead of powering it so that it returns. Any reason for that? For anyone else wondering how I fixed it: it was indeed the return issue. I had my turnbuckle set up in the accidental 1 in a million position where it would lock at fully extended. It would only return if there was an initial torque to return it. Manual calibration wouldn’t work; I tried that as well. i ended up just rotating the arm on the S54 actuator 180 degrees from the stock position and run no spring on it. It works perfectly now. Quote Link to comment Share on other sites More sharing options...
Adamw Posted November 28, 2022 Report Share Posted November 28, 2022 10 hours ago, Link2ThePast said: Kinda weird that it just shuts it off on the final step instead of powering it so that it returns. Any reason for that? I thought I explained it above. Before calibration the ecu has no idea which way is open or close and which way the motor has been wired. So it first powers the motor in one direction, zeros the TPS, then powers in the other direction, sets this to 100%. Then it turns off power to the motor, if it sees the throttle blade move backwards towards the "zero" position then it knows the calibration was done in the correct direction. If it turns power off and the blade doesnt move then it suggests the blade was already closed - therefore it has been calibrated "back to front". Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted November 28, 2022 Author Report Share Posted November 28, 2022 7 hours ago, Adamw said: I thought I explained it above. Before calibration the ecu has no idea which way is open or close and which way the motor has been wired. So it first powers the motor in one direction, zeros the TPS, then powers in the other direction, sets this to 100%. Then it turns off power to the motor, if it sees the throttle blade move backwards towards the "zero" position then it knows the calibration was done in the correct direction. If it turns power off and the blade doesnt move then it suggests the blade was already closed - therefore it has been calibrated "back to front" Sorry I must admit I only skimmed your initial response. I can see that you explained above, though admittedly I am unsure if I see it now more clearly because of your second explanation, so I appreciate the detail Adam. Quote Link to comment Share on other sites More sharing options...
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