Faulty throttle position or pedal position sensor (both sources). Misadjusted throttle position sensor (OBD-Codes.com). Open, shorted, corroded or chafed sensor wiring or connectors (both sources). Binding, damaged or carbon-coated throttle plate or throttle bore (both sources). Torn or jammed floor mats interfering with the pedal (RepairPal). Bad PCM or a PCM programming error, which is less likely (OBD-Codes.com).

Repair loose, corroded or chafed wiring and connectors. Clean a carbon-coated throttle body, or repair a binding or damaged throttle plate. Replace the throttle position or pedal position sensor if its voltage sweep glitches. Adjust the throttle position sensor to the factory spec if your vehicle's sensor is adjustable (OBD-Codes.com). Repair or reprogram the PCM only after the sensor and wiring check out (OBD-Codes.com).

P0124🔧 Air intake / throttle position sensorStop and fix promptly

P0124: Throttle Position Sensor A Circuit Intermittent (Meaning, Causes, Fixes)

Q: What does P0124 mean?

P0124 means the engine computer (PCM) has seen intermittent or erratic signals from the throttle position sensor (TPS) or accelerator pedal position sensor 'A' circuit. Common causes are a worn or misadjusted sensor, loose, corroded or chafed wiring and connectors, a dirty or binding throttle plate, or a jammed floor mat, and rarely a PCM fault. The throttle position sensor is usually a potentiometer on the throttle body: as the throttle opens, contacts drag across a circuit board inside the sensor and change its voltage on a 5-volt reference circuit. The PCM uses that signal for fuel delivery, ignition timing, EGR and engine load calculations. OBD-Codes.com says P0124 is stored when the PCM sees a certain number of intermittent or erratic signals from the sensor over a set period and under programmed conditions. RepairPal defines the code as the Throttle/Pedal Position Sensor/Switch 'A' circuit output being unreliable, and points out that on drive-by-wire cars the accelerator pedal also has a position sensor, with the throttle sensor confirming the throttle actually opened as requested. The sources differ on severity and symptoms: RepairPal rates it 'Urgent' and says many cars show nothing but the check engine light, while OBD-Codes.com lists hesitation, black smoke at startup, delayed cold starts and worse fuel economy. They also differ on causes: OBD-Codes.com lists a misadjusted sensor, a binding or damaged throttle plate and PCM programming errors, while RepairPal lists a carbon-filled throttle bore and torn or jammed floor mats. P0124 is a generic OBD-II code; P0120 through P0123 cover the general, range/performance, low and high faults in the same circuit.

Q: Can I keep driving with P0124?

Stop and fix promptly. Get this diagnosed promptly. RepairPal rates P0124 'Urgent' and says the computer may limit the car to 20 mph or less (limp home mode). OBD-Codes.com says it should be addressed with some urgency because the throttle position sensor matters so much to drivability. If the car hesitates badly, won't accelerate normally, or won't start reliably, don't drive it in traffic; have it diagnosed first.

Reviewed 2026-10-24 · Based on 2 cited source(s)

What P0124 means

The throttle position sensor is usually a potentiometer on the throttle body: as the throttle opens, contacts drag across a circuit board inside the sensor and change its voltage on a 5-volt reference circuit. The PCM uses that signal for fuel delivery, ignition timing, EGR and engine load calculations. OBD-Codes.com says P0124 is stored when the PCM sees a certain number of intermittent or erratic signals from the sensor over a set period and under programmed conditions. RepairPal defines the code as the Throttle/Pedal Position Sensor/Switch 'A' circuit output being unreliable, and points out that on drive-by-wire cars the accelerator pedal also has a position sensor, with the throttle sensor confirming the throttle actually opened as requested. The sources differ on severity and symptoms: RepairPal rates it 'Urgent' and says many cars show nothing but the check engine light, while OBD-Codes.com lists hesitation, black smoke at startup, delayed cold starts and worse fuel economy. They also differ on causes: OBD-Codes.com lists a misadjusted sensor, a binding or damaged throttle plate and PCM programming errors, while RepairPal lists a carbon-filled throttle bore and torn or jammed floor mats. P0124 is a generic OBD-II code; P0120 through P0123 cover the general, range/performance, low and high faults in the same circuit.

Severity: can I keep driving?

Stop and fix promptly

Get this diagnosed promptly. RepairPal rates P0124 'Urgent' and says the computer may limit the car to 20 mph or less (limp home mode). OBD-Codes.com says it should be addressed with some urgency because the throttle position sensor matters so much to drivability. If the car hesitates badly, won't accelerate normally, or won't start reliably, don't drive it in traffic; have it diagnosed first.

Common symptoms

Check engine light on
Often no other symptoms (RepairPal)
Hesitation on acceleration (both sources)
Hard starting, delayed cold starts, or in some cases no start (both sources)
Black smoke from the exhaust, especially at startup (OBD-Codes.com)
Worse fuel economy (OBD-Codes.com)
Limp home mode with speed limited to about 20 mph or less (RepairPal)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Faulty throttle position or pedal position sensor (both sources)
Misadjusted throttle position sensor (OBD-Codes.com)
Open, shorted, corroded or chafed sensor wiring or connectors (both sources)
Binding, damaged or carbon-coated throttle plate or throttle bore (both sources)
Torn or jammed floor mats interfering with the pedal (RepairPal)
Bad PCM or a PCM programming error, which is less likely (OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Make sure the floor mat isn't bunched up or caught under the accelerator pedal (RepairPal).
Inspect the throttle body for carbon buildup or damage, and check that the throttle moves and closes freely (both sources).
Check the sensor connector and harness for loose terminals, corrosion, or wiring rubbed through. Because the fault is intermittent, a loose connection is a prime suspect (both sources).
Write down the stored codes and freeze frame data, clear the codes, and drive normally to see whether P0124 comes back (both sources).
With a scan tool or voltmeter, key on and engine off, slowly open the throttle from closed to wide open and watch the sensor voltage. OBD-Codes.com says it typically rises smoothly from about 0.5 volts to about 4.5 volts; any drop-out or glitch points to the sensor or its wiring.

Typical fixes

Repair loose, corroded or chafed wiring and connectors
Clean a carbon-coated throttle body, or repair a binding or damaged throttle plate
Replace the throttle position or pedal position sensor if its voltage sweep glitches
Adjust the throttle position sensor to the factory spec if your vehicle's sensor is adjustable (OBD-Codes.com)
Repair or reprogram the PCM only after the sensor and wiring check out (OBD-Codes.com)

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

Catching an intermittent glitch often takes a lab scope or a road test comparing throttle position with engine load, airflow, RPM and road speed on a data-streaming scan tool (RepairPal)
Checking for a steady 5-volt reference and a good ground at the sensor connector using the correct wiring diagram (RepairPal)
Looking up technical service bulletins, which OBD-Codes.com says are especially helpful for intermittent faults
Setting TPS adjustment to factory specs with a voltmeter after replacement if the code keeps coming back (OBD-Codes.com)
RepairPal warns sensors are often replaced when the real problem was a dirty throttle body, a poor connection, chafed wiring, or a damaged floor mat

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Is it safe to drive with P0124?

RepairPal rates it 'Urgent' and says the car may go into limp home mode at 20 mph or less, though many cars show only the check engine light. OBD-Codes.com says to address it with some urgency. Get it diagnosed promptly, and don't drive in traffic if the car hesitates badly or won't accelerate normally.

What does 'intermittent' mean for P0124?

The sensor signal is dropping out or jumping erratically from time to time rather than staying steadily too high or too low. That's why both sources stress checking wiring and connectors and sweeping the sensor slowly while watching for glitches.

What's the difference between P0124 and P0122 or P0123?

P0122 means the circuit voltage is too low and P0123 means it's too high. P0124 means the signal is intermittent or erratic, and P0120 and P0121 cover the general circuit and range/performance faults in the same sensor.

How much does it cost to fix P0124?

Neither source gives a repair cost. The fix can range from fixing a floor mat or connector to cleaning the throttle body or replacing the sensor, so get it diagnosed and ask for a written estimate.

Sources

Last reviewed 2026-10-24. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.