Voltage at TPS at idle .65 and up to 2.75 at WOT is this adequate

I recommend you test the tps according to procedure below. Especially step 8. Suspect you will see drop outs in the voltage, which indicate sensor is worn out.
Operation

The Throttle Position Sensor (TPS) is mounted to the side of the throttle body and connects to the throttle blade shaft. The TPS is a variable resistor that provides the PCM with an input signal (voltage). The signal represents throttle blade position. As the position of the throttle blade changes, the resistance of the TPS changes.
The PCM supplies about 5 volts of DC current to the TPS. The TPS output voltage (input signal to the PCM) represents throttle blade position. The TPS output voltage to the PCM varies from about 0.5 volt at idle to a maximum of 4.0 volts at wide open throttle. The PCM uses the TPS input, and other sensor input, to determine current engine operating conditions. The PCM also adjusts fuel injector pulse width and ignition timing based on these inputs.
Testing

In order to perform a complete test of the TPS and related circuits, you must use a DRB or equivalent scan tool, and follow the manufacturers directions. To check the Throttle Position Sensor (TPS) only, proceed with the following tests.

1. Visually check the connector, making sure it is attached properly and that all of the terminals are straight, tight and free of corrosion.
2. The TPS can be tested using a digital ohmmeter. The center terminal of the sensor supplies the output voltage. The outer terminal with the violet/white wire is the 5-volt supply terminal and the black/light blue wire is the sensor ground terminal.
3. Connect the DVOM between the center terminal and sensor ground.
4. With the ignition key to the ON position and the engine OFF, check the output voltage at the center terminal wire of the connector.
5. Check the output voltage at idle and at Wide Open Throttle (WOT):
6. For 1996 vehicles at idle, the TPS output voltage should be greater than 0.35 volt (0.4 volt for the 2.4L engine). At WOT, the output voltage should be less than 4.5 volts (3.8 volts for the 2.4L engine).
7. For 1997 and later vehicles at idle, the TPS output voltage should be about 0.38-1.20 volts. At WOT, the output voltage should be about 3.1-4.4 volts.
8. The output voltage should gradually increase as the throttle plate moves slowly from idle to WOT.
9. If voltage measures outside these values, replace the TPS.
10. Before replacing the TPS, check for spread terminals and also inspect the PCM connections.

vacuum control unit possibly bad hose or unit is dirty,change fuel filter and check voltage regulator as well have starter alternator battery tested at local autoparts store for free

What wire are you reading 15 volts on? The ye/wh wire on pin 2 should read 5 volts, and the pk/og on pin 3 should have good ground. pins 1 and 4 should work opposite as the throttle plate moves (pin one ye/we voltage goes up on the way to WOT, pin 4 gr/wh voltage goes down on the way to WOT If you're getting anything higher than a 5 volt reference, check for a short to voltage from another wire in the harness. If that is no good, check the pin out from the ECM directly and see it it is pushing out too much on the reference wire

using a scan tool? depends on how the scan tool , interprets it
my scan tool (fancy) has absolute angle and adjusted.
Palmer software... best bang for buck.
when you turn the key on, the ecu sees true zero, (mechnically)
on newer cars the ECU learns this device.
usually a voltage from,. 0.5 to 1v.
on my 3 cars , i must calibrate it to 0.5v
this the ECU uses as 0 deg. adjusted.
or about 5% absolute but varies wildly from make and years.
why are you worried,?
if its linear from near min to max and don't glitch , its 100% GOOD>
do you want me to look yours up. at alldata.com and see if it even is calibrated?
see 7 to 50%here driving
http://www.fixkick.com/ECU/palmer/96M-log2w.jpg

the actual reading is not important
unless, your car must be set to 0.5v like mine
if not right , the idle controls are dead.
on newer cars this is auto calibrated or fixed.
the tps #1 purpose (if a small list ) is to enable enrich mode.
when you move your foot fast the ECU drops closed loop and then
goes rich, the faster the foot, the more reach,.
it does not set air fuel ratio;s just cruising.
The other main sensors do that.
ill list the other TPS jobs
i cut throttle TPS warns ecu of that, and cuts fuel.
cranking wide open throttle cuts fuel , unflood mode
WOT driving, go to enrich, WOT mode, about 12.5:1 AFR and drops
closed loop, who time. Un like enrich mode.
it also controls Dash pot effect and when EGR is active or not.

but idle actual valve is no t import. be it 5 or 10%
over 75% is WOT.
the device is very crude if you read the spec. mines
like 3000 to 5000 ohms. very very crude but very reliable.

Since you have replaced almost all of the parts, maybe the problem is in the wires. I would check for shorting and continuity on the tps harness. The wot signal is getting thru, but there may be issues in between idle and wot. The tps signal is on the dark blue wire. Set your meter to volts DC and measure the voltage on that wire bank-probing the connector wile some turns the key on and slowly pushes the throttle down. Do you see a gradual increase or does it stay flat and then jump? Check for the reference voltage on the other terminals. Also check the same wire voltages at the computer connector. Do they match?

Have you consider to check the battery power. I believe the main problem you have is either the battery or the alternator. Due to these two things with low voltage the brain ( ECU ) does not have the enough power to work. Good Luck.

The 3 wire Throttle Position Sensor (TPS) is mounted on the throttle body and is connected to the throttle blade.
The TPS is a 3wire variable resistor that provides the Powertrain Control Module (PCM) with an input signal (voltage) that represents the throttle blade position of the throttle body. The sensor is connected to the throttle blade shaft. As the position of the throttle blade changes, the resistance (output voltage) of the TPS changes.
The PCM supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The PCM receives an input signal voltage from the TPS. This will vary in an approximate range of from .26 volts at minimum throttle opening (idle), to 4.49 volts at wide-open throttle. Along with inputs from other sensors, the PCM uses the TPS input to determine current engine operating conditions. In response to engine operating conditions, the PCM will adjust fuel injector pulse width and ignition timing.
The PCM needs to identify the actions and position of the throttle blade at all times. This information is needed to assist in performing the following calculations:

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• 2001 JEEP GRAND CHEROKEE 4WD 4.0L MFI 6CYL REPAIR GUIDE
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• THROTTLE POSITION SENSOR

Cherokee, Grand Cherokee, 1999-2005
Throttle Position Sensor

• OPERATION
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Operation

The 3 wire Throttle Position Sensor (TPS) is mounted on the throttle body and is connected to the throttle blade.
The TPS is a 3wire variable resistor that provides the Powertrain Control Module (PCM) with an input signal (voltage) that represents the throttle blade position of the throttle body. The sensor is connected to the throttle blade shaft. As the position of the throttle blade changes, the resistance (output voltage) of the TPS changes.
The PCM supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The PCM receives an input signal voltage from the TPS. This will vary in an approximate range of from .26 volts at minimum throttle opening (idle), to 4.49 volts at wide-open throttle. Along with inputs from other sensors, the PCM uses the TPS input to determine current engine operating conditions. In response to engine operating conditions, the PCM will adjust fuel injector pulse width and ignition timing.
The PCM needs to identify the actions and position of the throttle blade at all times. This information is needed to assist in performing the following calculations:


Ignition timing advance Fuel injection pulse-width Idle (learned value or minimum TPS) Off-idle (0.06 volt) Wide Open Throttle (WOT) open loop (2.608 volts above learned idle voltage) Deceleration fuel lean out Fuel cutoff during cranking at WOT (2.608 volts above learned idle voltage) A/C WOT cutoff (certain automatic transmissions only)

Removal & Installation

3.7L & 4.0L

1. Disconnect TPS electrical connector.
2. Remove TPS mounting screws.
3. Remove TPS.

To Install:
The TPS is mounted to the throttle body. The throttle shaft end of throttle body slides into a socket in the TPS. The TPS must be installed so that it can be rotated a few degrees. (If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs). The TPS will be under slight tension when rotated.

1. Install TPS and retaining screws.
2. Tighten screws to 7 Nm (60 inch lbs.) torque.
3. Connect TPS electrical connector to TPS.
4. Manually operate throttle (by hand) to check for any TPS binding before starting engine.

4.7L

1. Remove air duct and air resonator box at throttle body.
2. Disconnect TPS electrical connector.
3. Remove two TPS mounting bolts (screws).
4. Remove TPS from throttle body.

To Install:
The throttle shaft end of throttle body slides into a socket in TPS. The TPS must be installed so that it can be rotated a few degrees. If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs. The TPS will be under slight tension when rotated.

1. Install TPS and two retaining bolts.
2. Tighten bolts to 7 Nm (60 inch lbs.) torque.
3. Manually operate throttle control lever by hand to check for any binding of TPS.
4. Connect TPS electrical connector to TPS.
5. Install air duct/air box to throttle body.

Hope this helps

This is indicating that the TPS Sensor is either out of calibration or defective however it sends dc low voltage to the computer like at idle it is reading its lowest value and when you tag the pedal(WOT wide open throttle) pedal to the metal...it will read its highest just to let the computer know if you are idling, driving slow or really stepping on it, these various TPS readings gives the computer the proper information to allow the different sensors such as the O2 sensor etc. and the injectors how to behalve through electronic voltage signals all the while keeping your vehicles engine running at its top performance for efficientcy and for clean exhaust emmisions.
The shop scanners are the best to use when replacing or resetting the TPS as with the proper testing for any other electronic sensors on your vehicle, these scanners are a bit too expensive for any one to be owning working on their vehicles, it just doesn't seem to be cost effective.
I think you would be better served letting a certified tech take care of this matter for you.
Hopes this helps

Check the TPS (Throttle position sensor) wire lead and replace the TPS if any signs of damage or failure.

The Throttle Position Sensor (TPS) is used to send input signals to the Powertrain Control Module (PCM) to indicate the current angle of the throttle blade.

Theory/Operation:
This sensor is a variable resistor that has a 5 volt reference signal applied to it by the PCM. The TPS sends signals back to the PCM in the range of approximately 1 to 4 volts, depending upon the throttle shaft angle. The PCM uses these input voltages to determine the current position of the throttle.
The PCM uses the voltage signals from the TPS and other input sensors to determine the proper air/fuel mixture and ignition timing for certain operating conditions. Some of these operating conditions are: acceleration, deceleration, idle, and wide open throttle.


Typical Readings:
An input voltage of approximately 1 volt indicates a minimum throttle opening, idle, or deceleration condition. An input voltage of approximately 2 volts indicates a cruise or light acceleration condition. An input voltage of approximately 4 volts would indicate a maximum throttle opening or wide open throttle condition.
NOTE: The following procedure tests the TPS only.

1. The TPS can be tested with an analog voltmeter. The center terminal of the TPS is the output terminal.
2. With the ignition key in the ON position, check the TPS output voltage at the center terminal wire of the connector. Check this at idle (throttle plate closed), and at wide open throttle (WOT).
   • At idle, TPS output voltage should be approximately one volt. The output voltage should increase gradually as the throttle plate is slowly opened from idle to WOT.
   • At wide open throttle, TPS output should be approximately 4.5 volts.

As always, check the service manual for the proper procedures and specifications for your particular vehicle.

Thank you using Fixya and good luck.

yes the throttle has a sensor on it that measures in volts how far down you have the gas pedal, the computer then uses this to determine how much gas to send to the engine, this is a simplified explanation but mostly correct, the test the dealer wants to do indicates a possible TPS code, correct? what is the code?