Question about 1989 Cadillac Sedan DeVille

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TPS voltage readings

We need to know the voltages from signal wire in respect to wide open throttle do to idle for a 1989 Cadillac Deville V8 DFI injection.

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This requires a certain operation to set. If you really need to know reply and I can help.

Posted on Jun 20, 2010

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What are the parameters in ohms for the 1994 probe se tps ?


They are easier to test on the car 3 wires 1) 5 volt reference 1) signal return (testing this wire) last wire is ground. place + lead of a volt meter on the signal return wire with key on engine off negative lead on block or battery resting closed throttle should .3 to .8 volts slowly increase throttle opening and watch meter it should increase without voltage ever going lower E.G 1.0,1.1,1.2,1.3,.09,1.5 the .09 is a drop sensor bad this should continue to wide open throttle with a ending reading of 4.95 and above voltage. rdo this several times to catch a glitch.

May 11, 2014 | 1994 Ford Probe

1 Answer

03 caravan showing codesP0123 and P0121. Can anyone help me with this. The van is not shifting gears properly. Thanks!


Hi there:
P0121 - Throttle Position Sensor/Switch A Circuit Range/Performance

The Throttle position sensor is a potentiometer that measures the amount of throttle opening. As the throttle is opened, the reading (measured in volts) goes up. The powertrain control module (PCM) supplies a 5 Volt reference signal to the throttle position sensor (TPS) and usually a ground also. A general measurement is: at idle = .5 Volts; full throttle = 4.5 Volts. If the PCM detects that the throttle angle is greater or less than it should be for a specific RPM, it will set this code.


Symptoms of a P0121 trouble code could include:

Malfunction Indicator Lamp (MIL) illumination (Check Engine Light or Service Engine Soon light)
Intermittent stumble on acceleration or deceleration
Blows black smoke on acceleration
No start


A code P0121 may mean that one or more of the following has happened:
TPS has intermittent open or short internally
Harness is rubbing and causing an open or short in the wiring
Bad connection at the TPS
Bad PCM (less likely)
Water or corrosion in connector or sensor

Possible Solutions:
1. If you have access to a scan tool, see what the idle and WOT (wide open throttle) readings are for the TPS. Check if they're close to the specifications mentioned above. If not, then replace the TPS and re-check.

2. Check for an intermittent open or short in the TPS signal. To do that, you can't use a scan tool. You'll need an oscilliscope. The reason is because scan tools take samplings of many different readings over just one or two data lines and can miss an intermittent drop out. Hook up your oscilliscope and watch the signal. It should sweep up and down smoothly with no drop outs or spikes.

3. If no problems were noticed, perform a wiggle test. Do this by wiggling the connector and harness while watching the pattern. Does it drop out? If so, replace TPS and re-check.

4. If you have no TPS signal, check for 5 Volt reference at the connector. If it's present, check the ground circuit for open or shorts.

5. Make sure the signal circuit isn't 12V. It should never have battery voltage. If it does, trace circuit for short to voltage and repair.

6. Look for any water in the connector and replace TPS as necessary.


P0123 Code - Throttle Position Sensor/Switch A Circuit High Input
A P0123 code means that the the car's computer has detected that the TPS (throttle position sensor) is reporting too high a voltage.


Symptoms may include:
Rough idle
High idle
Surging
other symptoms may also be present


A code P0123 may mean that one or more of the following has happened:
TPS not mounted securely
TPS circuit short to ground or another wire
Faulty TPS
Damaged computer (PCM)

Possible Solutions
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, carefully inspect all wiring and connectors that lead to the TPS. More than likely the problem is with the TPS wiring. Check the voltage at the TPS (refer to a service manual for your vehicle for this specific information). If the voltage spikes or is too high (over 4.65 volts with key on, engine off), then that is indicative of a problem. Carefully trace each wire from the TPS wiring harness to check for breaks, rubbing against other components, etc.


Hope helps

Apr 19, 2012 | 2003 Dodge Caravan

1 Answer

Where is the thorttleposition sensor on 2001jeep cherokee


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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Cherokee, Grand Cherokee, 1999-2005
Throttle Position Sensor

Print


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

Dec 31, 2011 | 2001 Jeep Grand Cherokee

1 Answer

P0123 Just put new Tps and it is showing this code now can adjust the TPS?


DTC P0123 - Throttle Position Sensor/Switch A Circuit High Input
This code means that the the car's computer has detected that the TPS (throttle position sensor) is reporting too high a voltage. Were codes deleted after this job? This is a code for TPS voltage high.

The sensor voltage should never be greater than 5volts. It normally reads .5 to .8 volts at idle (closed throttle). The orange and dark blue is the signal wire, black and light blue is the sensor ground, and the violet and white is the 5volt supply wire. You will need to back probe the signal wire to find the value. It is possible the signal or ground wires are open. Or the PCM is faulty.

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Hope this helps (remember to rating this free answer).

Oct 10, 2011 | 1999 Dodge Ram

3 Answers

Autozone hooked the car up to its diagnostic computer it read that the throttle sensor unit was bad...I replaced it then drove it and the check engine light can on. They diagnosed it again and said it was...


Can you send us exactly the OBD Codes - Mercury Diagnostic Trouble Codes that Autozone find there? With this code number could send other details.

Keep in touch.

Sep 28, 2011 | 1998 Mercury Villager

1 Answer

96 nissan quest code p0120 p1705 the O/D flushes after startup. TPS was replaced but code still exists. Rough idle, loss of power and fuel economy.


this is an obd2 trouble code table, it can help you understand the meaning of code.
and for p0120
the Causes:
Sticking throttle return spring
MAP or TPS connector corrosion
Misrouted harness causing chafing
Bad TPS
Bad PCM
Possible Solutions:
If you have access to a scan tool, with KOEO (Key on engine off) observe the TPS voltage. With throttle closed, voltage should be about .45 volts. It should gradually sweep upwards to approximately 4.5 to 5 volts as you depress the throttle. Sometimes only a scope can capture an intermittent glitch in the TPS signal voltage. If you notice a glitch in the TPS sweep voltage, replace the TPS.
NOTE: Some TPS sensors require fine adjustment. If you aren't comfortable with using a DVOM (Digital Volt Ohm meter) to adjust the new TPS, then it's best to take the vehicle to a shop. If the voltage is not .45 volts (+or- .3 volts or so) with the throttle closed or if the reading is "stuck" then unplug the TPS connector. With KOEO check for 5 volts reference voltage present at the connector and a good ground. You can check the signal circuit for continuity by jumping a fused wire between the ground circuit of the TPS connector and the signal circuit. If the TPS reading on the scan tool now reads zero, then replace the TPS. However if that doesn't change the reading to zero, then check for an open or a short on the signal wire and if none is found, suspect a bad PCM. If manipulating the TPS wiring harness causes any change in idle, then suspect bad TPS.

Jul 11, 2011 | Nissan Quest Cars & Trucks

1 Answer

95 cadillac reading code current p105 sometimes engine light comes on sometimes harder to start than normal, idles up and down up on stopping


Symptoms Symptoms of a P0105 check engine light code may include:
  • Poor running engine
  • Engine runs rich
  • Engine won't idle
  • Engine backfires through tailpipe
  • Engine misfire under load or at idle
  • MIL (Malfunction Indicator Lamp) illumination
  • In some extreme cases there may be no symptoms other than MIL illumination
Causes A P0105 DTC could be caused by:
  • MAP sensor vacuum hose disconnected or plugged
  • Bad MAP Sensor
  • Bad TPS
  • Damaged or problematic MAP sensor connector
  • Damaged or problematic TPS connector
  • Damaged wiring
  • Short to reference voltage on signal circuit of MAP Sensor
  • Loss of ground to MAP sensor or TPS
  • Open on signal circuit of MAP sensor
  • Bad PCM
Possible Solutions Using a scanner or code reader, turn the ignition on and engine OFF; what does the MAP sensor voltage read? It should be about 4 Volts for sea level. If you are at a higher altitude, it should decrease about half a volt or so for each 1,000 ft. of altitude (this will vary from model to model) Or if you have a separate MAF (Mass air flow) sensor on your vehicle, they are usually equipped with a Barometric pressure reading. If so, the Baro reading should match the MAP reading (they both measure ambient air pressure). If they're roughly equal, then, check for Freeze Frame data of the MAP sensor (if available).
NOTE: Freeze Frame data is the PCM recording a fault when it happens. It captures the readings of the various PIDS (parameter identifiers)available to troubleshoot what happened. It's like a recording of the problem as it happened. At idle a typical MAP sensor Voltage reading should be about a volt, and at WOT (wide open throttle) it should approach 4.5 to 5 Volts. As for the TPS, at idle, the voltage reading is about 1 Volt or less. As the throttle is opened the reading will increase to 4.5 Volts at WOT. Do the two readings make sense? For example, if the TPS reading on Freeze Frame data shows 2.5 Volts (indicating partial throttle) does the MAP sensor indicate a reading that isn't at either extreme? Using the Freeze Frame data (if available) compare the MAP reading to the TPS when the problem occurred. This can help you identify what happened
If you have no access to Freeze Frame data then check if the MAP sensor voltage changes when you apply vacuum to it. You can do this by mouth or a vacuum pump. The voltage should increase as you apply vacuum. If the reading doesn't change as you apply vacuum, make sure there are no obstructions in the hose to the sensor. If the hose is clear, the MAP sensor is usually bad, but it doesn't rule out the following from causing the problem: Does the MAP sensor appear to be stuck at less than .5 Volts? Then:
NOTE: This code shouldn't set if the MAP is stuck at extremely low voltage, however, I'm adding it in because there's no way to know for certain for which vehicles a low voltage condition may set a P0105
  1. Inspect the wiring harness and MAP sensor connector. Repair any damage
  2. Unplug the MAP sensor connector. Also, at the PCM connector, remove the MAP sensor signal wire and check for continuity to the MAP sensor connector. If there is infinite resistance, then repair open in MAP signal circuit. If the signal wire has continuity to the MAP sensor connector, then check for 5 volt reference voltage to the connector and a good ground. If both are present, then re-install all removed wiring and replace the MAP sensor.
Does the MAP sensor appear to be stuck at full 4.5 voltage? Then:
  1. Inspect the wiring harness for damage. Repair as needed
  2. Remove the MAP sensor signal wire from the PCM connector. With a voltmeter measure the voltage with KEY ON ENGINE OFF. Is there 4.5 Volts? If so, unplug the MAP sensor and recheck. If it is still present, then repair short between the signal wire and 5 volt reference wire.
  3. If unplugging the MAP sensor causes the voltage to disappear, check that the ground is intact. If it is, then replace the MAP sensor due to internal short.

Jun 17, 2011 | 1995 Cadillac DeVille

1 Answer

My 1993 cadillac deville feels as if the rpm's are running high (idle seems too high) the service engine soon light ocassionally comes on and I get the error code E30. Anybody have any ideas??


The error is indicating that the Throttle Position Sensor (TPS) is out of the normal range with respect to the Idle Speed Control (ISC). Try something really simple and inexpensive first by removing the air ducting between the air filter box and the throttle body. Clean the throttle body interior and throttle plate with a cloth sprayed with WD40. Turn the throttle plate by pushing it at the top with your fingers and clean the throttle throat behind the plate as best you can. Reassemble the ducting and ensure that there are no air leaks at the junctions and no splits. Turn the key to position 2 (engine not running) and depress the accelerator pedal to the floor and then back up again. Start the car and nine times out of ten that should fix it. The TPS measures the opening angle of the throttle plate. The TPS is device consisting of a circular carbon track with a slider, corresponding to the throttle plate, sweeping along it. It as three wires to it, two to provide the 0 to 5 volt range along the length of the carbon track and the third to measure the voltage at the contact point of the slider. To check the TPS measure the voltage of the middle pin of the connector when the ignition is at position 2 (engine off) as you push the throttle plate open and closed by pressing on the accelerator pedal. The voltage should alter in a smooth continuous way. Any drop outs of signal indicate a worn carbon track and the TPS should be replaced.

May 09, 2011 | 1993 Cadillac DeVille

1 Answer

Car starts has no power until the gas pedal is almost to the floor. In 2nd the tach is at 3500 rpm and won't shift until i let up on the gas. It also hesitates and is using more gas than usuall.


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.

Mar 08, 2010 | 2002 Oldsmobile Alero

3 Answers

1997 Dodge Ram Stalls


"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.

Jan 10, 2009 | 1997 Dodge Ram 1500 Club Cab

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