high idle,code p0122

[cjsuds13]

2003 venture 3.4l 140k driving to store van strarted rev up,was hard to stop.placed van in park idle went high,no tack,turn van off at store,started up everthing ok,started driving idle went up again,hard to stop,went on hiway with foot off pedal and cruise off van got up to 70kms.got home check engine light on,got code p0122 tp sensor low voltage.has new tp sensor.any ideas would help.

[lesterl]

Check the harness, check the connector for corrosion, meter the connector ignition on, one wire should have 5vdc, one should have 0vdc, the other should have from 0.5vdc to 4.8vdc (the sensor should be hooked up.) Open and close the throttle by hand (ignition still on, engine off) and watch the meter reading on the 0.5-4.8vdc wire and watch for a smooth increase/decrease in the voltage.

[Loonylani]

My 1998 Venture is doing exactly the same thing. I would like to know how to fix it. If the voltage is wrong then what?
Let me start at the beginning though. In april 09 the van stopped running and it turned out to be that plug under the van that runs the fuel pump etc. Then again this April 2010 it did the same thing (it ran fine before this incident throttle-wise). We towed it home and ran voltage tests, all which showed ok. We got the codes (P0122) exactly as states low voltage to TPS. We cleaned out the plug and prongs and made sure there was good contact. Now it is running again, but when I leave home after initial start-up it surges and the van accelerates on its own. When you put it in park it revs up and stays there. If you shut it off for a minute or 2 it starts and idles fine. Then when you start driving it, it takes off and has a constant high idle. Put it in park and it revs. What on earth could have happened when repairing the plug that would make it do that? It was ok before, idle-wise.
Any suggestions would be helpful. If the voltages are off now, then what? If they aren't then what? Most people state that the TPS is not the problem, but the wiring? What wiring should we look at?

[lesterl]

This happened after you repaired the fuel pump plug?

I would take a meter and back probe the connection at the TPS, put the black lead to ground somewhere (engine block would be good), backprobe with the red lead the 3 wires on the TPS, 1 should have 5vdc, 1 should read 0vdc, the last one should read between 4.8vdc (WOT) to 0.8vdc (IDLE) ---- Test with ignition on and engine off. While you are on the third terminal vary the throttle slowly open to WOT back to IDLE and back several times while watching the voltage, if steady and linear the TPS is good.

[cjsuds13]

replaced tp sensor was good for a few months,started happening again.checked connector that runs through floor,looks ok.The wires at the tps were pinched under air cleaner tube,repaired by soldering and shrink tubing.Could the iac be causing this problem.Had van running,disconected iac,nothing happened,idle stayed normal.Disconected what i beleave is the evap purge solinoidjust behind iac and the idle went high.Could evap cause high idle.

[lesterl]

Check over your vac lines over good for cracks/ leaks.