Checking TPS?

[6.9PoweredScout]

ok i know the pedal is throttle by wire what do i check to make sure its good? is there a sensor on "the other end" to check too? sometimes my transmission downshifts flawlessly, other times it "falls" into the next gear and the truck runs out of power till it builds boos again.....

[old man dave]

The TPS is a simple potentiometer. 0-5v output and 5 volts to it. You should be able to read a smooth change in voltage between maybe 0.5 volts to 4 volts or so while operating the pedal. The IVS switch is just that, open or closed.

[6.9PoweredScout]

so test it hooked up?

[STROKER #1]

Originally Posted by 6.9PoweredScout

so test it hooked up?

You need to put a voltmeter across the GY/W and the GY/R wires on the connector to the TPS. With the key on, watch the voltage across the range of the throttle to see if there is any flat spots. You should see no less than 3.7 volts at idle position and no more than 4.5 volts at full throttle. The third wire, (BRN/W), is the ref. voltage and should be 5 volts all the time.
IVS is on or off as mentioned.

[6.9PoweredScout]

Easy enough. Thanks. And whats IVS stand for?

[STROKER #1]

Originally Posted by 6.9PoweredScout

Easy enough. Thanks. And whats IVS stand for?

Just put your mouse over the Green acronim and you will get the meaning.

[6.9PoweredScout]

Thats hard to do on a phone... Haha

[old man dave]

Idle Validation Switch. It tells the PCM to start sensing the Throttle Position Sensor. If this isn't working, the engine RPM will not change from idle when depressing the pedal.

[old man dave]

Originally Posted by STROKER #1

You need to put a voltmeter across the GY/W and the GY/R wires on the connector to the TPS. With the key on, watch the voltage across the range of the throttle to see if there is any flat spots. You should see no less than 3.7 volts at idle position and no more than 4.5 volts at full throttle. The third wire, (BRN/W), is the ref. voltage and should be 5 volts all the time.
IVS is on or off as mentioned.

I've seen voltages as low as less than 1 volt at idle using AE and full throttle at voltages ranging from 3.5 volts to 4.5volts. Cold checking resistances at minimum of 400-500 ohms on the sensing legs to about 5000 ohms checking across the reference voltage legs. Voltages above 4.6 volts is rumored to make the PCM revert back to idle state.