| Author | Message | ||
     Arch379 |
I just recently installed a Buell race ECM. I wanted to first reset the TPS settings in ECMSpy but noticed the lowest the TPS voltage would go is 3.5v, no matter how much I backed out the idle adjustment screw? Does this sound normal. I read that it should go all the way down to 0.0 volts before doing the reset? This might be unrelated, but I noticed in my diagnostics section the CPS signal was in red and had the number 5. Any help is appreciated. | ||
| Ochoa0042 |
isnt this why is must be reset, to zero out the system voltage reading on the TPS?  | ||
| Azxb9r |
isnt this why is must be reset, to zero out the system voltage reading on the TPS? Yes...the TPS reset sets the zero point of the TPS. That is why you need to make sure that the throttle plate is completely closed when you do the reset. If it does not go to zero with the throttle plate closed, that means that you definitely need to do the reset. | ||
| Sifo |
The voltage wont go to zero. All the TPS reset does is tell the ECM the the voltage it sees corresponds to zero degrees of throttle opening. | ||
| Azxb9r |
Oops...my bad. I was thinking throttle percent not throttle volts. 3.5 is higher than it should be though, if I remember correctly mine gets down well below 1 volt while doing the TPS reset | ||
| Azxb9r |
You will want to verify that the 3.5v reading you are getting on the scan tool is accurate. Use a volt meter to verify the output from the TPS. The TPS has 3 wires- Violet/Yellow is the TPS signal wire Red/White is the 5v reference Black/White is the ground Check the TPS output and see if the voltage matches the reading on your scan tool. If it does not, you have a software problem. If the voltage does match, check the reference voltage. 4.9v-5.1v is good. If that is ok, check the ground circuit. Voltage should be less than .05v (50mv). If the ground and the 5v reference are good, and your TPS signal voltage will not get down around 1v, you have a sticking or bad TPS. If your reference voltage is too high, you have a bad ground or a bad ECM. If the voltage on the ground circuit is high...you have a bad ground. If you do not have a volt meter, you can unplug the TPS while you watch the scan tool reading. If it drops to 0v you know that the scan data is good but not much else. | ||
| Sifo |
Wouldn't the scan tool simply be reporting the voltage according to the ECM? | ||
| Azxb9r |
In theory yes, but sometimes scan tools lie. Since you are going to be there testing your reference voltage and ground circuit, the extra few seconds it takes to verify the output is time well spent imo. I hate replacing parts unnecessarily  |
