P2122 OBD-II Trouble Code: Throttle Position Sensor/Switch A Circuit Low Input

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P2122 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2122 code

P2122 is a diagnostic trouble code (DTC) for "Throttle Position Sensor/Switch A Circuit Low 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. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P2122 DIAGNOSTIC Get a fair and transparent estimate upfront

Check Engine Light

P2122 trouble code definition

The P2122 OBD-II trouble, or fault, code means that the vehicle’s on-board computer has detected low voltage in the throttle position sensor (TPS), which is usually below 0.17 volts.

What the P2122 code means

The registration of the P2122 trouble code simply means that low voltage has been detected in the TPS. Depending on the vehicle’s make and model, this detection may trigger a forced engine shutdown, forced idle, or forced reduction in power output to prevent overloading circuitry.

What causes the P2122 code?

While there are multiple potential causes for the P2122 fault code registering, one of four components is likely defective - the throttle position sensor, the throttle actuator control motor, the throttle position actuator, or the pedal position sensor. If all four of these parts are in good working condition, the cause may lie in damaged wiring, connectors, or grounds.

What are the symptoms of the P2122 code?

While the most obvious symptom of the P2122 code is the illumination of the Check Engine Light on the dashboard, the following symptoms may also be noticeable:

How does a mechanic diagnose the P2122 code?

To begin diagnosing the cause of the P2122 trouble code, first verify its existence. A qualified technician can do this through the use of a specialized scan tool that collects data about the vehicle’s performance and reports any anomalies in the form of OBD-II trouble codes. Once a mechanic has performed a scan and the P2122 code registers, then further tests and/or inspections are necessary to narrow down potential culprits.

The next step is often a visual inspection of all wiring and connectors; if damaged wires or connectors are found, they are replaced. The mechanic then clears the trouble code from the computer’s memory and uses the specialized scan tool again. If the P2122 code does not register, the issue is likely resolved. On the other hand, if the code registers again, additional diagnostic efforts are needed.

Using a digital volt/ohmmeter, a mechanic can then check the voltage readings through the throttle position sensor, the throttle actuator control motor, the throttle position actuator, and the pedal position sensor. This will help determine if any of these components is responsible for the low voltage detected by the on-board computer, so faulty parts can be replaced. A technician can also check the voltage through wiring, grounds, and the CAN bus network in order to repair or replace any worn or damaged parts.

Once repairs have been made, the mechanic will clear the OBD-II fault code, scan for anomalies again, and possibly test drive the vehicle to ensure the issue has been satisfactorily resolved.

Common mistakes when diagnosing the P2122 code

Once the P2122 code registers, mechanics sometimes make the following mistakes:

  • Failing to address trouble codes in the order of appearance, when multiple codes register
  • Failing to verify the existence of the P2122 code
  • Failing to clear the P2122 code from the on-board computer following repairs

How serious is the P2122 code?

Although some vehicles do not enter a no-start condition after the P2122 fault code registers, it does not mean the issue that caused it should be ignored. Whether the root cause of the code registering is a faulty component or loose wire or something else entirely, failing to repair the problem has the potential to negatively affect other parts or systems. This ultimately can incur greater cost and hassle in repairs than it would in prompt attention to the matter.

What repairs can fix the P2122 code?

Once the registering of the P2122 trouble code is deemed valid with the use of a specialized scan tool, the following action(s) may be necessary:

Additional comments for consideration regarding the P2122 code

In the diagnosis of the P2122 code, it is possible for the process to take up to several hours. This is due to the potential need for multiple tests with a scan tool or voltage meter, hands-on inspections, and test drives. In being thorough from the start, the chance of other related problems cropping up is greatly reduced.

Need help with a P2122 code?

If you would like help in diagnosing and addressing the P2122 OBD-II fault code, reach out to YourMechanic to be connected with a qualified technician. This diagnostic and repair professional can even come to your home or office for your convenience or safety. Book an appointment online, get a quote for the cost of repairs, or discuss the possibilities with a representative at 1-800-701-6230.

trouble codes
Check Engine Light
throttle position sensors

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P2122 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.5/5

Number of Reviews

3,484

Rating Summary
3,176
153
40
23
92
3,176
153
40
23
92

Richard

10 years of experience
415 reviews
Richard
10 years of experience
This is the second time I’ve had Richard work on my car. He always does an outstanding job and is quick, knowledgeable and professional. Highly recommended!!
2012 DODGE CHALLENGER - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Michael

13 years of experience
372 reviews
Michael
13 years of experience
Mike was an absolute professional when he arrived. He walked me thru the whole process of my repairs and also made good recommendations for preventive issues. His mechanical knowledge and good customer services was a breath of air and greatly appreciated :-)
2007 CHEVROLET AVALANCHE - CHECK ENGINE LIGHT IS ON INSPECTION - MARIETTA, GEORGIA

Rodrigo

10 years of experience
85 reviews
Rodrigo
10 years of experience
Rodrigo was exactly on time, very professional and friendly. He assessed my car, let me know the exact problem when a previous mechanic from a shop in my area was unable to. I felt he was very honest and sincere letting me know the level of urgency that I deal with the issue. Absolutely no pressure. I will absolutely use Rodrigo the next time I need anything to do with my car and will tell everyone about him. This is such a great service, I will never go to another mechanic again. It is so convenient. I couldn’t be happier. :)
2013 SMART FORTWO - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Ricardo

8 years of experience
223 reviews
Ricardo
8 years of experience
Great service and was very helpful on what maintenance my vehicle needed and what to expect in the future. Would definitely recommend to anyone and will.
2004 MITSUBISHI LANCER - CHECK ENGINE LIGHT IS ON - LOS ANGELES, CALIFORNIA

More related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...

Related questions

Q: Intake maifold runner control is stuck open

Hello, thanks for writing in about your 2001 Mazda Miata. Due to this trouble code, the intake manifold runner control will need to be replaced. If this is not done you can cause serious damage to your car. If you...

Q: Jeep stopped acclerating, brakes locked up, power steering fluid everywhere 2000 Jeep Grand Cherokee

Hi - first task is to check for problem codes (Check Engine light) - these will be helpful. From your symptoms, and the sequence, I believe the engine lost oil suddenly (failed oil cooler line or front crank seal?), and...

Q: Throttle body position is at 40% at idle and I just replaced tbs

You need to check the throttle plates and see if they look like they are open without touching the gas pedal. If they are, then disconnect the throttle cable and see if the plates close. If it closes, then you...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com