I don't seem to have any supply voltage to my tps.

TPS wiring may be frayed.

You are still getting high or low voltage at tps? What is the voltage and do you have a unstable idle? Put you + lead on terminal 3 and - lead on terminal 1 turn ignition on and check voltage to be at approximately 5 volts. You can also back probe with it connected at center wire and ground probe to a good ground at engine. Turn ignition on it should read between 0.20 - 0.90 slowly manually open throttle it should rise all the way to 4.5 voltd at full open. If its bad change tps if no 5.0 volts from pcm on first test check connections at pcm. The center tps connector supply wire comes from pin 22 and connection 3 ( which is 5 volt supply ) comes from pin 6. You should be able to back probe pin 6 turn ignition on and have 5 volts. If not 5 v brain has problem.

How is the battery voltage ?

Is the battery over 4 or 5 years old?

Check the tps connector

Check the alternator for a/c ripple

Back probe tps

You have two sides
5v to .02
.02 to 5v
grd
ref 5v

something like that,i don't have
any diagram for your veh

Your so called tune-up is not even in the
area of the problem

The cps is for #1 cylinder recognition,not the issue either

Study-- don't listen to anyone,you have a lot to
remember back on & be proud of.

Your looking for something that would put more than
5v that the pcm outputs,so a voltage spike from somewhere

Hello www_ropesmor,

This code P0123 is Throttle position sensor circuit high input.

There four basic reasons for this code.

1. An open or short to ground between the TPS (throttle position sensor) and the ECM (Engine control module).
2. A short to battery voltage between TPS and the ECM.
3. A short between the TPS wires.
4. A faulty TPS.

See below for connector diagrams.

First, with scan tool monitor TPS with throttle closed voltage should be
I f you don't have a scan tool, back probe terminal 1with a volt meter to ground and you will see the voltage as outlined above otherwise follow the steps below.


1.Check to see if there is about 5 volts at the TPS; with engine off key on disconnect the TPS back probe the harness side terminal 3 to ground with a volt meter if there is about 5 volts go to step 2 if about 5 volts if not repair the 5 volt circuit.

2. Probe the harness side terminal 2 to chassis ground with a volt meter, if voltage above .02 repair circuit 2 short to voltage. If voltage is .02 volts or below go to step 3.

3. Probe the harness side terminal 1 to ground with volt meter if below .5 volts go to step 4 if not repair short to battery between TSP harness and ECM connector

4 Turn the ignition off and disconnect the ECM connector . With an ohm meter measure the resistance between the ECM (terminal C18) and TPS ground circuit it should be below 1 ohm. Measure the resistance between the ECM (terminal C8) and TPS signal circuit it should be below 1 ohm. If not repair the open circuit.

After faulty circuit is found and repaired clear code and verify repair.







I hope this helps.

Regards,

netvan

Where is it located? The TPS is found on the exterior of the throttle body on the opposite end of the throttle shaft to the accelerator linkage arm. It usually consists of a small black plastic unit with an electrical connector attached to it.

How does it work? The TPS is a variable resistor made up of an arc shaped carbon track with an applied voltage of 0 to 5 volts along its length and a sliding contact that picks up the voltage at any point along it. The device has three electrical connections, two provide the voltage range along the carbon track and the third (most often the middle connection) sends a voltage to the ECU in accord with the position of the sliding contact point on the arc. This siding contact arm is attached to the end of the throttle shaft. As the throttle shaft rotates, opening and closing the throttle plate, the sliding contact sweeps up and down the arced carbon track providing voltage readings to the ECU; 0 volts for closed to 5 volts for fully open.

When the engine is at idle the TPS output should signal the ECU that the throttle is closed (low volts) and therefore the ECU should either open the Idle Air Control (IAC) valve or (on some engines) engage the idle speed control motor to maintain the engine idle speed. Sometimes a micro contact switch on the throttle body exterior associated with the throttle shaft is used to detect and confirm when the throttle plate is fully closed.

How to check? The socket for electrical connection with the TPS has 3 pins, one for 'ground', one for 5 volts 'reference' and a third (generally the middle one) for 'signal' output. Back probe the signal pin in the connector to the TPS. Attach the positive lead of a voltmeter to the probe and measure the voltage output as the throttle plate is rotated. If working correctly the meter should show a voltage consistent with the throttle position from approximately 1 volt when closed and 5 volts when fully open. What is looked for is smooth voltage increase with throttle change. If there are drop outs in the throttle transition voltage signal or if there is no transition then the TPS is faulty.

How to fix? If the track is dirty causing drop outs, try cleaning it with residue-free electrical cleaning spray. If the track is worn it is perhaps easiest to replace the complete device. In some instances it may be possible to adjust the location of the central mount of the TPS contact arm along the throttle shaft by a few millimeters and in the process cause a fresh concentric region of track to be used.

Could be a problem with the throttle position sensor. If the carbon track on which the throttle plate slider contact runs has dirt on it or is worn then this would interrupt signal to the ECU. The TPS has three pins in the socket. Two (usually the outer two) supply the 5 volts reference and 0 volts ground to the carbon strip. the middle pin measures the voltage 'tapped' by the throttle position sliding contact. Disconnect the TPS lead and with a voltmeter simply measure the resistance between one of the outer pins and the middle pin as the throttle plate is opened and closed. The response should be smooth chnage in resistance with no 'drop-outs'. If a drop is consistently detected at a particular throttle plate position then the TPS needs to opened and cleaned if dirty or replaced if faulty.

wheather your a2 .0 or 2.5 at idle key on engine off its is 0.7V to 1.1 V. you test it by doing a sweep, with your volt meter,voltage should increase with smooth throttle movement there should be no drop out or glitches and at wide open throttle you should reach 4.5 V , (***) wide open throttle

OK this is the loop. You put your foot on the gas and the ECM calls on the throttle actuator control (TAC) motor to open the throttle plate. A throttle position sensor (TPS) on the throttle plate shaft feeds back to the ECM the position of the throttle plate. If there is an interruption of signal either to the TAC or from the TPS the ECM sees the lack of agreement and shuts the system down and sets the throttle to idle or 16 degrees to allow you you to crawl home. In the old days when the throttle position was dictated physically by the throttle cable directly I would have suggested that, with the engine off, the throttle be pushed to the maximum and released quickly to reset the TPS and allow the ECM to recalibrate. First check that the throttle body interior and plate are spotlessly clean. If the throttle interior is dirty the throttle plate has to opened wider to allow air passed the film of grime lining the throttle and the ECM may see this as a lack of accord between the TAC requested and the larger than expected TPS return signal. Check that the wiring connections to the throttle body are clean and bright. Check that the TPS interior is clean and no grime has got between the throttle shaft mounted slider contact and the circular contact strip - if you suspect that this is an issue spray clean with electrical contact cleaner (only use this as it leaves absolutely no residue). Open the throttle plate fully using you fingers and allow it to snap closed on its spring. If you suspect the TPS as the cause of the error here is some generic detail:-

How to check? The socket for electrical connection with the TPS has 3 pins, one for 'ground', one for 5 volts 'reference' and a third (generally the middle one) for 'signal' output from the throttle plate slider. Back probe the signal pin in the connector to the TPS. Attach the positive lead of a voltmeter to the probe and measure the voltage output as the throttle plate is rotated (use your fingers to turn it). If working correctly the meter should show a voltage consistent with the throttle position from approximately 1 volt when closed and 5 volts when fully open. What is looked for is smooth voltage increase with throttle position change. If there are drop outs in the throttle transition voltage signal or if there is no transition then the TPS is faulty and replace it.

Hello! The Throttle Positioning Sensor (TPS) is defective...It is bolted to the throttle body...It is a round black device about the size of a 1/2 dollar, with a mounting hole on each side...It has a 3 wire connector...Wire colors are...Gray/White...Gray/Red...And Brown/White...Cost $55...Use 2 safety pins...Push the pointed end into the rear of the connector on the Gray/White wire and the other on the Gray/Red wire...Do not disconnect the connector...Set a volt meter to read a maximum of 5 volts...Place the + probe on the Gray/White wire...The - probe on the Gray/Red...Turn the key to on...Voltage must be less then 1 volt (.85)...If not TPS is defective...

Do not move probes...Start the engine (if you can)...Watch the meter...Slowly increase the throttle...Voltage must rise to 4 volts (wide open throttle)...As voltage rises...If the voltage skips, jumps, or acts erratic the TPS is defective...

Guru...............Saailer



I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

"TPS" is your throttle position sensor located on the right side of your throttle body (if you are facing your engine) the function of the tps is to send imput to your pcm (power control module) by the movement of the throttle plate at idle/part throttle/wide open. the pcm will adjust air/fuel mix/egr functio/timing of spark based on tps imput by way of voltage signals. you can check for a bad tps sensor by using a voltmeter and back probing the tps connector. there are 3 wires with the connector tange facing up, the 3 wires are sensor ground (the wire closest to you) the middle wire is the sensor signal wire and the wire furthest away from you is the 5v supply wire. turn ign key to "on" (do not start engine) voltage should be between 0.2-1.4v with probes still inserted into the plug, slowly turn throttle pulley toward wide open throttle, youe readings should slowly rise to about 4.5v - IF NO VOLTAGE PRESENT- check wiring harness for supply voltage (around 5v) ground (0.3v) if both supply voltage and ground voltage present AND no output voltage tps FAULTY TPS. remove/replace tps. if voltage values exist, but are less than what they should be, look for problem with wiring harness, or bad pcm. my other thoughts are partially plugged fuel filter/pressure sensor, or a vacuum leak gremlin somewhere.