No TPS, IAT, & CLT from stim

[calibum1323]

Hello any help in this field would be greatly appreciated. I built my MS-2 v3.0 board and i am currently in the process of testing things and figuring out right settings for my car but ive hit a dead spot. I have the stim plugged in. MS-2 has power and everything but I have no control over TPS, IAT, & CLT. RPM's work good and if i turn the O2 a hair in the right spot it will work. Not sure how to test for this. I tested at the DB-37 with a DMM to see if the stim was working right and the ohms changed when i turn the knob so i know its not that. Think it could be a communiction problem. Software downloaded fine onto the MS-2. Havnt tested the IAC or anything yet. Would like to figure out what my issue is first of why i cant control my TPS, IAT, & CLT with the Stim. Are there any tests i could run at the 40 pin processor or anything to see whats going on? Thanks

[Matt Cramer]

Yes, check the voltage at the ADC inputs and see if they move when you turn the knobs.

[calibum1323]

I dont know where exacty to check the adc inputs. i checked at the DB37 connector to see if my stim was working and when i turn the pots the voltage did change no probem but obviousy thats on the end of the stim lol. where can u test the adc inputs coser to the ms2 daughtercard or on it so i can see if its not getting the information for the computer to read it. thank you

[Matt Cramer]

Here's what pin goes with what sensor input:

Pin 22 - MAP
Pin 23 - IAT
Pin 24 - CLT
Pin 25 - TPS
Pin 26 - Battery voltage (reads 1/6 of actual voltage, from bootloader header)
Pin 27 - O2

Remember, pin 20 is at the upper left hand corner of the socket as it mounts "upside down" on the board.

[calibum1323]

Thanks for the input matt. now are you talking about removing the daughtercard and testing the pins on the daughtercard or removing the daughtercard and testing on the 40 pin connector on the pcb board itself. or just leaving the daughtercard plugged in and testing it right from the top of the pins. also what am i measuring for at these pins. thanks sorry to bug out with so many questions. just trying to get things figured out so i can hopefully say i built my own computer that works rather than say i bought one already built lol. thanks for the help.

[Matt Cramer]

Test it with the daughter card in place. See if the voltage on the pins moves when you turn the corresponding pot on the Stim. (With the obvious exceptions of battery and MAP readings, which aren't controlled by the Stim.)

[calibum1323]

Well you see there is another issue i am having. i will be sure to test those tonight and see how things turn out but my map reading is pinned all the way to about 290 or so and my battery is pinned also and reads like 29 volts when im only using 12 volts on the stim itself.

[Matt Cramer]

Well you see there is another issue i am having. i will be sure to test those tonight and see how things turn out but my map reading is pinned all the way to about 290 or so and my battery is pinned also and reads like 29 volts when im only using 12 volts on the stim itself.

What's your VREF voltage look like? If it's pulled low, everything else starts reading high.

[calibum1323]

Well if you are talking about the VREF for the TPS and things like that i havnt measure the voltage coming from that wire yet but i know when i was assymbling the megasquirt in the first couple of steps, after installing the 40 pin connector it says to check the voltage at pins 19 and 20 for 5 volts. What i had gotten with a DMM was 4.7. Now this i thought was ok seeing as how they only said if u get anything higher then there is a problem. There was never anything that said about slightly lower. Unfortunately i do not have the megasquirt on hand right now to read those for you but i will post them up of what i found out probly tm afternoon. thanks for your time and patience of helping me out.