Skip the auto shop - Our mechanics make house calls

P0124 OBD-II Trouble Code: Throttle Pedal Position Sensor/Switch (TPS) A Circuit Intermittent

Check Engine Light

P0124 code definition

Throttle Pedal Position Sensor/Switch (TPS) A Circuit Intermittent

What the P0124 code means

  • P0124 is the generic OBD-II code that indicates the TPS sensor circuit A output voltage goes below or above the sensor's expected range; the signal is erratic and fails intermittently.

What causes the P0124 code?

  • The TPS circuit A signal is erratic compared to TPS circuit B.

  • The TPS circuit signal A may be going in and out of specifications of .2 volts or below.

  • The TPS circuit signal A may be going in and out of high specifications of 4.54 volts.

What are the symptoms of the P0124 code?

  • The Engine Control Module (ECM) will go in and out of failsafe mode when the sensor goes in and out of specifications.

  • The ECM will turn the Check Engine Light on and go into a failsafe mode.

  • The ECM cuts current to the throttle actuator so the throttle valve closes to approximately 6 degrees of throttle plate opening.

  • The fuel injection and ignition is used to control engine speeds.

  • The vehicle speed is limited to very slow with limited throttle response.

  • The engine may idle higher or lower than normal.

Note: The symptoms above are determined by the manufacturer failsafe ECM strategy for the vehicle during a TPS failure and may vary between manufacturers and vehicles.

How does a mechanic diagnose the P0124 code?

  • Scans and documents the codes received, views the freeze frame data to see the conditions when the code was set to try and duplicate the failure

  • Clears the OBD-II fault codes and retests the vehicle to see if the code comes back

  • Checks all TPS connections and wiring for intermittent problems

  • Compares the data between TPS circuit A and B on the scanner while performing a wiggle test to try and find an intermittent wiring or connector issue

  • Repairs the wiring or connections as needed

  • Replaces the TPS, as pinpoint tests dictate, and performs a road test after clearing the codes

Common mistakes when diagnosing the P0124 code

  • Not visually inspecting for the source of the problem first

  • Not scanning, documenting, clearing and retesting the codes to verify any failures before attempting any repairs

  • Replacing the TPS sensor without verifying through tests that there is a problem

  • Not comparing TPS sensor A and B to be within specification before and after repair or replacements

How serious is the P0124 code?

The P0124 code can cause the engine's ECM to go into and out of failsafe mode, which will cause various drive issues until repairs are done such as lack of acceleration, high idle, bucking or jerking, limited speeds, or stalling, depending on the manufacturer's failsafe mode strategy.

The TPS sensor's failure can also affect other systems and cause them to work erratically, such as the transmission, brakes, and suspension to name a few.

What repairs can fix the P0124 code?

Additional comments for consideration regarding the P0124 code

  • The P0124 code may be accompanied by other TPS codes, so following the manufacturer pinpoint tests for each code received may be needed to find and fix the failure.

  • Most failures for code P0124 involve a defective TPS sensor, or sensor connector corrosion or damage.

  • All TPS codes will cause the ECM to go into failure mode and drive symptoms will be the same for all the TPS codes.

Need help with a P0124 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P0359 OBD-II Trouble Code: Ignition Coil I Primary/Secondary Circuit Malfunction
P0359 code definition The P0359 code indicates that a fault has been detected in one of the vehicle’s ignition coils, generally the number 9 coil. This code can also be associated...
P0477 OBD-II Trouble Code: Exhaust Pressure Control Valve Low
P0477 code means that the PCM has detected an abnormally low voltage reading often due to the exhaust back pressure control valve circuit.


Related questions

Q: Check Engine light comes on randomly now, not happy about it

I would recommend going back to the person that replaced the plugs to see if there is a warranty issue for the repairs needed. You will need to have the vehicle's computer scanned as well as diagnosis of any codes....

Q: Will a bad O2 sensor damage my car's computer?

The engine control unit (ECU) is a possible cause of the O2 sensor fault codes but not the most likely. Your vehicle is equipped with 4 O2 sensors. Bank 1 is the driver's side. Bank 2 is the passenger side....

Q: Had new Mass airflow sensor put on an now I'm getting a code p0171 what could it be

This relates to a lean fuel condition which can be caused by many different things such as: Intake air leaks Faulty front heated oxygen sensor Ignition misfiring Faulty fuel injectors Exhaust gas leaks Incorrect fuel pressure Lack of fuel...