zaihas.chan Posted November 28, 2023 Report Share Posted November 28, 2023 Hi, Need help to clarify if the AUX/INJ/IGN spare output can be use to provide 5V PWM output to external controller? if yes can it be set internally or via external pull-up resistor to 5V? Quote Link to comment Share on other sites More sharing options...
Adamw Posted November 28, 2023 Report Share Posted November 28, 2023 They are low side drive. The aux outputs have a 12V pull-up so will be pulled up to 12V when off. ign and injector drives dont have pull-ups so you could add your own 5V pull-up into the wiring if you really needed 5V. If it is a PWM device however it probably doesnt care what voltage is used - as the name suggests it is using pulse width, not voltage. Quote Link to comment Share on other sites More sharing options...
zaihas.chan Posted November 29, 2023 Author Report Share Posted November 29, 2023 @Adamw Im feeding signals to toyota/daihatsu EPS to avoid it from running in safe mode. The ECU that im using is XtremeX wire-in. Currently I identified 2 signals required (both 50% duty cycle signals) from factory service manual of that EPS. Speed: 5V square wave (~17Hz at 20kph) confirmed can use 5V pull-up from INJ/IGN) - not sure if the controller can accept >5V high signal. I'm just try to be safe and feed 5V square signal. RPM: 12V square wave (~33Hz at 1000rpm) for 4 piston so if im using AUX for engine speed (RPM), regardless of which AUX (1-8) we should be able to get 12V high (pulled to 12V internally) and 0v low since it is low side drive? Am i right? Quote Link to comment Share on other sites More sharing options...
Vaughan Posted November 29, 2023 Report Share Posted November 29, 2023 Are you already outputting a tacho signal to the factory dash? Do you still have the factory dash and is it outputting a speed signal still? Based on dealing with Toyotas previously you should just be able to use the regular Aux outputs Quote Link to comment Share on other sites More sharing options...
zaihas.chan Posted November 29, 2023 Author Report Share Posted November 29, 2023 @Vaughan Nope im not sending tacho output to factory dash. Dash is AIM, which the input is from CAN bus. For speed signal the output come straight from Xtreme ECU to the EPS. So does the EPS controller can accept 12V signal with no issue for speed? Quote Link to comment Share on other sites More sharing options...
Vaughan Posted November 29, 2023 Report Share Posted November 29, 2023 I have never used an EPS controller so can't say with any real certainty that it will accept the speed and tacho signal directly from the ECU but I would definitely recommend trying it and seeing if it works. Note you can use the test PWM function to send particular frequencies out without having the vehicle running or driving to see if it works. Quote Link to comment Share on other sites More sharing options...
zaihas.chan Posted November 29, 2023 Author Report Share Posted November 29, 2023 Yep. That is my plan. I just cant confirm if the EPS controller can accept 12V input for speed signal. Afraid i fried the controller LOL. Thus my plan is to either use voltage level shifter or simply use IGN/INJ output with 5V pullup resistor for speed signal. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted November 29, 2023 Report Share Posted November 29, 2023 The Aux outputs output a solid ground and a weak pullup to 12V not an actual 12v signal and so should be safe. Quote Link to comment Share on other sites More sharing options...
Adamw Posted November 29, 2023 Report Share Posted November 29, 2023 As a general rule, any electronics in a car is usually designed to be able to handle "12V", any input would typically have a clamp diode or series resistor to protect it. We cant say that for certain for this particular device unless someone else has tried, but I can say I have never fried any automotive PWM device connected direct to a normal aux, including many fan controllers, fuel pump controllers and alternators that all used a 5V high level pwm originally. Quote Link to comment Share on other sites More sharing options...
zaihas.chan Posted November 30, 2023 Author Report Share Posted November 30, 2023 awesome thanks guys! Quote Link to comment Share on other sites More sharing options...
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