S-AFC Throttle Position Sensor Voltage

[Besso]

So basically the AFC is showing 5.124V all the time when the throttle is either open or closed. It is set right to 4cyl. and the ^ up arrow for the throttle. My logger shows the correct throttle position and the right wires have been connected and re-checked. Any ides?

 

[steve]

New SAFC install?
If your logger is reading the correct voltage but the SAFC isn't then I'd still bet on a wiring issue.

 

[Besso]

it's been hooked up for a while now. Wiring has also been totally torn down and re-dun by somebody else with no luck. I could check the actual voltage of the wire with a multi-meter.

 

[spyderturbo007]

The arrow should be pointing in the North East direction. Does the TPS value on the SAFC change as you drive? Keep in mind, that the SAFC's TPS value is not going to be correct. When you drive the car, the TPS sends a voltage to the ECU indicating throttle position. Since the SAFC has no reference value for TPS percentages, it assumes that the lowest voltage it "sees" is 0% and the highest voltage is 100%.

So it's very common to see an actual TPS value (on the logger) of 90%, but the SAFC still reads 100%. Never go by the SAFC, always the logger.

 

[steve]

The sensor check screen on the SAFC will display the measured voltages on the various inputs.
I assumed that where the OP was getting the voltages reported since it's wasn't specified as percentages.

 

[Besso]

Yea, the arrow is positioned in the north east direction and the sensor check shows 5.124 all the time, no matter where the throttle is. Which makes the AFC think that you are in WOT even at idle. There are no other wire that could be tapped near the ecu that would show a 5v value, right?

 

[steve]

Please update your profile and tell up what car you have. Need to know that to look at the correct pinouts.

 

[Besso]

I'm pretty sure that it says 1992 Galant VR-4

 

[steve]

The TPS signal is on pin 19. Green with White stripe wire, the 6th in from the bottom right on the biggest connector.