P0121 is a generic OBD-II code which indicatesthat the Engine Control Module (ECM) has seen the TPSsensor circuit A learned output voltage go above or below thesensor's expected range when compared to TPS sensorcircuit B.
Code P0121 triggers when the Throttle/PedalSensor/Switch "A" Circuit sends irrational data to the PowerTrainControl Module or PCM.
The automotive trouble code P2135 throttle/pedalposition sensor/switch A/B voltage correlation refers to a problemrelated to the throttle's ability to open and close properly. Athrottle position sensor (TPS) is situated opposite thethrottle linkage connection on the throttle plate.
Symptoms of a Faulty Throttle Position Sensor
- An unexplainable bucking and jerking in the vehicle.
- Sudden idle surges.
- Sudden engine stalling without any apparent reason.
- Hesitation while accelerating.
- Sudden surges in speed while driving on the highway.
- Intermittently flashing of check engine light for no apparentreason.
Follow the plastic duct from the air filter housing upto the throttle body. Remove the duct and locate thethrottle cables and rotating mechanism. Rotate thethrottle mechanism and spray the cleaning solventaround the inside of the throttle body. Give it a moment towork and then wipe out the crud.
The Differential Speed Sensor measures vehiclespeed. If it malfunctions or fails, the transmission canstop shifting or shift late and harsh. It may alsocause the automatic transmission to go into failsafe.
The automotive trouble code P2138 throttle/pedalposition sensor/switch D/E voltage correlation refers to a problemrelated to the throttle's ability to open and close properly. Athrottle position sensor (TPS) is situated opposite the throttlelinkage connection on the throttle plate.
P2101 is an OBD-II generic code for theengine control module (ECM) detecting the throttle actuator control(TAC) went out of the range of the circuit causing an open circuitto be detected in the TAC motor.
Engine stalling often
In some cases a damaged throttle kicker actuatorwill impact the idle ability of the engine after it has been undera load. When the idle goes too low, the engine will shut offor stall.Symptoms of a Bad or Failing Throttle KickerActuator
- Throttle hesitation. Most of the time, the engine responds tothrottle pressure applied by the driver without stumbling orhesitation.
- Poor fuel economy. Similar to the issue above, when the kickeractuator is sending bad information to the onboard computer, theair to fuel ratio will be inaccurate.
- Engine stalling often.
Accelerator Pedal Release Position LearningProcedure.
Make sure that the accelerator pedal is fully released.Turn ignition switch “ON” and wait at least 2 seconds.Turn ignition switch “OFF” wait at least 10 seconds.Turn ignition switch “ON” and wait at least 2seconds.Symptoms of a Bad or Failing ThrottlePosition Sensor. Common signs include lacking power whenaccelerating, rough or slow idle, stalling, inability to shift up,and the Check Engine Light coming on.
Know what price you should pay to get yourvehicle fixed.
The average cost for a throttle bodyreplacement is between $577 and $688. Labor costs areestimated between $92 and $117 while parts are priced between $485and $571. Estimate does not include taxes andfees.Incorrect air flow can result in poor engineperformance, reduced power, poor idling and other problems. Withinthe throttle body is a throttle plate, which opens asyou press down the gas pedal. The throttle body is locatedbetween the air intake assembly and intake manifold.
Today's modern cars, trucks, and SUVs are all equippedwith an electronic throttle control system that contains anaccelerator pedal position (APP) sensor. Thissensor's primary job is to monitor the position ofthe throttle pedal and send an electronic signal to open thethrottle body as you depress the gas pedal.
The way your car gets moving involves multipleworking parts inside your vehicle. The first step of caracceleration is the throttle to the engine. When your throttlepedal gets closer to the floor, more air is sucked in to rotate thecrankshaft faster. These functions allow you to accelerate on theroad.
Use the cleaning solvent, something like acarburetor fluid and a clean piece of cloth, to remove thegrime and dirt around the area of the TPS unit. Now thatyou are sure all the surfaces are cleaned thoroughly, it'stime to put the sensor back, or if needed, go in for athrottle position sensor replacement!
Know what price you should pay to get yourvehicle fixed.
The average cost for a throttle positionsensor replacement is between $170 and $226. Labor costsare estimated between $58 and $74 while parts are priced between$112 and $152. Estimate does not include taxes andfees.How to Replace a Throttle Position Sensor
- Materials Needed.
- Step 1: Locate the sensor.
- Step 2: Disconnect the negative battery cable.
- Step 2: Remove the sensor electrical connector.
- Step 4: Remove the sensor mounting screws.
- Step 5: Remove the sensor.
- Step 1: Install the new sensor.
- Step 2: Install the sensor mounting screws.
Symptoms of a Bad or Failing Throttle PositionSensor
- Car won't accelerate, lacks power when accelerating, oraccelerates itself.
- Engine won't idle smoothly, idles too slowly, or stalls.
- Car accelerates, but won't exceed a relatively low speed, orshift up.
- Check Engine Light comes on, accompanied by any of the abovebehaviors.
A throttle position sensor (TPS) is asensor used to monitor the air intake of an engine.The sensor is usually located on the butterflyspindle/shaft so that it can directly monitor theposition of the throttle. Modern day sensors arenon contact type.
Loosen the throttle position sensor retainingscrew with a Phillips-head screwdriver. Adjust theTPS by moving it back and forth until the voltage is between4.0 and 5.5 volts. Hold the TPS in place and tighten theretaining screw with the Phillips-head screwdriver.
At idle is should be zero or a couple ofdegrees. Press down on the gas pedal very S-L-O-W-L-Y until thethrottle is all the way open. You should see thepercentage of throttle opening gradually increase to 100percent at wide open throttle.
The throttle position sensor works as an inputtool that sends signals to the engine control unit. The sensorworks around certain parameters and when these parameters aremet or are not met, the sensor sends the correspondingsignals to the engine control unit.
When a TPS goes bad, then the car's throttlebody won't function properly. It could either stay shut or itwon't close properly which is a severe issue. When thethrottle gets stuck in an open position than yourvehicle will receive too much air and cause it to have a high orfluctuating idle.
Replacing the Throttle BodyGasket
It should be replaced everytime the throttlebody has undergone any repair or service. It should also bechanged when there is an evident leak on thematerial.A throttle actuator and throttle body aregenerally the same part, the actuator is fully computerized(no cable) with no IAC (idle air control) valve. These devicescontrol the volume or amount of air that enters the engine via thedriver's accelerator pedal.
In summary, you can clean the throttlebody all you like, but the fact is, if your engine is worn,your intake and throttle body will continue to get dirty.Don't remove the throttle body to clean it; you don'tneed to. Cleaning your throttle body likely won't doanything to solve an idle problem.
Does electronic throttle body need to beprogrammed after replacing? Throttle body warning lightcomes. Try this: Get in your truck, turn the key to ONposition (do not start the engine!) and within 3seconds push the accelerator pedal to the floor and let itback.
Symptoms of a Bad or Failing Throttle Body
- Dirt, grime, and carbon deposits on the inside of the housing.Dirt and grime can build up inside the housing, causinginterruption in air/fuel flow.
- Electrical problems.
- Vacuum leaks or an incorrectly adjusted throttle stop.
- Poor or high idle.
The lightning bolt on the dash means thatthere is a problem with the electronic throttle controlsystem in your vehicle. Slowly depress the accelerator pedal allthe way to the floor. Slowly release the accelerator pedal until itis all the way back up at the rest position.
