The TPS error code P0123 appears only when the AC is on
I had the throttle position sensor replaced on the truck along with the connections and cables, because I was getting an error code P0123. The code indicates the throttle position sensor circuit high voltage. The code was cleared. However, each time I turn the AC on, this happens again. There is a low charge in the AC system, but no error codes appear. The AC compressor is working properly. When I drive the car without AC on, there is nothing out of the ordinary. Why does this code appear with the AC on?
Experienced mechanics share their insights in answering this question :
Hello. The low charge in the A/C system is going to cause the A/C compressor to work harder than it should. This will put a greater load on the engine and may cause your throttle position sensor to give a bad reading. Have a certified technician set the A/C system to the proper levels and see if the P0123 code continues. Having the throttle body cleaned may also help fix this problem. If you need help with this, a certified technician from YourMechanic can come to your car’s location to diagnose the code more thoroughly in order to have this corrected.
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P0123 is a diagnostic trouble code (DTC) for “Throttle Pedal Position Sensor/Switch (TPS) A Circuit High Input“. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation.
The easiest way to reset your throttle position sensor is to unhook the negative cable from your battery for up to five minutes or to remove the fuse for your engine control module.
A P0122 code is the generic OBD-II code defined as “Throttle Pedal Position Sensor/Switch (TPS) A Circuit Low Input.” This code relates to the vehicle`s Engine Control Module (ECM) and TPS Sensor Circuit A output voltage and is triggered when the voltage falls below the sensor`s anticipated range.
A P0123 trouble code means that the PCM has recorded a reading from the TPS that exceeds the normal 4.5 volts for more than two seconds. A fault like this means that the sensor either has a short or has failed.
7.1 Turn the key to ignition on, Engine kill switch positioned on but do not necessarily start the engine. 7.2 Rotate the throttle to full position and back to zero/idle position. Do this twice. 7.3 After this you will see a dialog box, saying Auto Calibration Completed.
The TPS is usually mounted on the throttle body (the housing that contains the throttle valve).
If you start to experience engine misfires, stalling, or rough idling when the car is stopped, it can also be a warning sign of a failing TPS.
To calibrate the unit, turn the vehicle`s ignition to ON but do not start the vehicle, hold down the ← → button for 5 seconds, the throttle controller screen will show a 15 second countdown. 5. During the countdown period press the accelerator pedal completely to the floor and hold for 1-2 seconds, then release.
Accelerator Pedal Release Position Learning Procedure.
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 2 seconds.
Based on the received voltage, the onboard computer can calculate the idling (below 0.7V), the full load (about 4.5V), and the opening speed of the throttle valve.
A faulty throttle body is one of the common causes of code P0121.
With the vehicle off, turn the key to the “On” position, but do not start the car. Hold the TPMS reset button until the tire pressure light blinks three times, then release it. Start the car and wait about 20 minutes for the sensor to refresh.
Most throttle sensors are three-wire. They require a 5V reference, a ground, and then output a 0-5v signal dependant on the position of the sensors shaft in relation to its body..
A malfunctioning TPS will cause your engine to run poorly. Generally the engine will idle fine but will have difficulty accelerating. This is because the computer isn`t telling the engine to inject as much fuel as is required, while at the same time airflow is increasing.
Do you have to reset computer after replacing throttle position sensor? After replacing the throttle position sensor in your engine, if the engine light was on and has a pending code, the code should go away. If the code doesn`t, however, then the ECM (engine computer module) will need resetting.
The high voltage condition from the O2 sensor is indicating a lack of oxygen in the exhaust or other related problems, such as a leaking fuel injector or a broken up catalyst inside.
Bad throttle position sensors can cause high idle without causing the Check Engine Light to illuminate.
Cleaning fuel injectors is generally not a do-it-yourself project, but you can clean the throttle body on your vehicle with common tools and specialized spray cleaners. While throttle-body cleaning is good preventative car maintenance, it should also help engine drivability.
The TPS checks the amount of air/fuel mixture being delivered to the engine, while the throttle body temperature sensor monitors the temperature of the air/fuel mixture and the actual throttle body.
The throttle body plays a large role in controlling the fuel and air mixture in your engine. The proper mixture needs to be achieved in order for your engine to run smoothly and properly. Once this part fails, it needs replacing rather than repairing.
Increase Throttle Response with Aftermarket Throttle Bodies
More air volume and speed is a surefire way to increase horsepower and throttle response at any given RPM. It is easy to achieve this at high RPM when the engine sucks in substantial amounts of air on its own. But coming off idle is another story.
Lubricate valves, cylinders, injectors, and rings. Remove varnish, dirt, carbon and other deposits from the throttle body and throttle plate.
– Make sure the ignition is on. – Make sure the adapter is connected to OBD2 port. – Connect to OBD2 device. – Press on throttle reset button and wait few minutes until the process is completed.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
The TPS error code P0123 appears only when the AC is on
ANSWER : Hello. The low charge in the A/C system is going to cause the A/C compressor to work harder than it should. This will put a greater load on the engine and may cause your throttle position sensor to give a bad reading. Have a certified technician set the A/C system to the proper levels and see if the P0123 code continues. Having the throttle body cleaned may also help fix this problem. If you need help with this, a certified technician from YourMechanic can come to your car’s location to diagnose the code more thoroughly in order to have this corrected.
Read Full Q/A … : The TPS error code P0123 appears only when the AC is on
I had my ECS replaceed and my TPS and the code for TPS was gone but the ECS code came on after 5 miles is it possible the new one
ANSWER : There is a possibility the new module is faulty, but there may be something else going on with the car as well. Wiring can be an issue with these vehicle so consider hiring an experienced technician like one from YourMechanic to loo at the car and offer a personal diagnosis. You can have bad knock sensors offering false readings or some faulted wiring.
Read Full Q/A … : The TPS error code P0123 appears only when the AC is on
I have a Code P0601 on the PCM. I replaced the PCM, and now I have a code P0118, code P0123, and code P0193.
ANSWER : Hi there, the short answer to your question is no . A PCM with a P0601 (which is a memory module error in the PCM) cannot reliably retrieve codes for the codes you list (P0118 – coolant temp sensor, P0123 – throttle position sensor, P0193 – fuel rail pressure sensor.
Most likely, the P0601 prevents the PCM from getting any codes from the engine sensors. The memory module error may cause in data corruption for collected sensor values, lose of data over multiple sampling periods, or failure of the data collection to work at all. Replacing the PCM was a necessary expense.
If you need assistance with the "new" codes, I would recommend having a Check Engine Light inspection completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose the new error codes and get an accurate assessment of the repairs needed.
Read Full Q/A … : The TPS error code P0123 appears only when the AC is on
Camshaft position sensor error code P0343
ANSWER : Hello. The P0343 code indicates there is no signal from the passenger side cam position sensor (Bank 1 actually). Given you have changed the sensor, this would suggest a wiring or connector issue. Your mileage would also make me anxious about timing chain guides, tensioner and timing chain – a chronic maintenance item on BMW V8s with this sort of mileage. While the timing chain service is a bit expensive, the alternative is even more so. I recommend having a certified technician from YourMechanic to thoroughly inspect the Check Engine Light and proceed with the appropriate repair.
Read Full Q/A … : The TPS error code P0123 appears only when the AC is on
Check Engine Light is on – codes P0313, P0299, P0304
ANSWER : Hi there. Based on what you’ve described, this could be a combination of faults between 2 or more things; however, I don’t believe the coils and spark plugs are at fault. One of the codes is set during a low fuel misfire (lean condition), one is specifying a misfire on cylinder 4, and one is a turbo related code; all based on a generic code investigation.
The make and model of the vehicle helps, but is not necessary at the moment. When a low fuel pressure misfire is set, there is a lean condition that has been detected by the sensors and one of the codes is telling us in which cylinder this is occurring. A possibility is a restricted fuel injector, loose injector harness, poor pin fit in the wire harness, and an air leak near that cylinder’s port in the intake manifold.
I’m leaning more towards a leak or crack somewhere creating an air leak since we also have a turbo related code stored and an intermittent rough start when cold. I strongly suggest having a qualified technician perform an inspection to determine the root cause. YourMechanic has several available technicians that can assist you with a Check Engine Light inspection and determine exactly what is giving rise to codes P0313, P0299, and P0304.
Read Full Q/A … : The TPS error code P0123 appears only when the AC is on
2008 VW Jetta AC not cold
ANSWER : Hi Allen. By far the best way to have your AC system correctly diagnosed is by having an AC inspection completed first. By having one of our professional mobile mechanics come to your location to diagnose the issue correctly, it significantly minimizes the mistakes in completing the wrong service. In your case, the issue could be as simple as needing to have the AC system recharged, or there is an existing leak that needs to be repaired before refilling the refrigerant. Best economic bet is to have the AC inspection completed first.
Read Full Q/A … : The TPS error code P0123 appears only when the AC is on
Error code P0101 MAF sensor circuit range
ANSWER : Hi – do you mean the code is P0101 (rather than P1010)? The P0101 code is mass air flow sensor. In any case, given the behavior of your engine and the Check Engine scenario you describe, yes, a dirty Mass Air Flow sensor, or dirty Idle Air Control valve would behave as you describe. They should be cleaned and checked. A low battery should not cause the problem you describe. If you need assistance with this issue, a certified YourMechanic technician can be dispatched to your location to perform one of the following services on your vehicle:
Mass Air Flow Sensor Replacement
Idle Control Valve Replacement
Check Engine Light is On Inspection
Read Full Q/A … : The TPS error code P0123 appears only when the AC is on
07 Honda Fit Code PO420. Car missing at idle when AC is on and has trouble accelerating, especially up hills, more so with AC on
ANSWER : Hi there.The catalytic converter has two oxygen sensors. One oxygen sensor is positioned in front (upstream) of the catalytic converter and the other oxygen sensor is positioned at the rear (downstream). If the upstream oxygen sensor is working properly, its readings should fluctuate from when the car is at operating temperature and when running in a closed loop. When the oxygen sensors have readings that are similar to each other, it is an indication that the catalytic converter is not working as intended. If the voltage of the downstream oxygen sensor decreases, and begins to fluctuate like the upstream oxygen sensor, it means that the oxygen levels are too high and the Powertrain Control Module (PCM) will store the P0420 trouble code. This could be caused by a cracked exhaust manifold, damaged sensors or catalytic converter or electrical harness that controls the the sensors. It would be a good idea to have a professional mechanic complete an engine is misfiring inspection.
Read Full Q/A … : The TPS error code P0123 appears only when the AC is on
