P2122 Throttle Position Sensor D Circuit Low Input
OBD2 Error Codes

P2122 Throttle Position Sensor D Circuit Low Input

Technical description Errors P2122

Low level of an input signal in a chain of the sensor of position of a butterfly valve / pedal / switch "D"

P2122 is a Diagnostic Trouble Code (DTC) for "Throttle Position Sensor/Switch A Circuit Low Input". This can happen for several reasons and it is up to the mechanic to diagnose the specific cause of this code being triggered in your situation.

What does this mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code, which means it applies to OBD-II equipped vehicles. Although general, specific repair steps may differ depending on the brand / model.

P2122 means that the vehicle computer has detected that the TPS (Throttle Position Sensor) is reporting too low a voltage. On some vehicles, this lower limit is 0.17–0.20 volts (V). The letter "D" refers to a specific circuit, sensor, or area of ​​a specific circuit.

Did you customize during installation? If the signal is less than 17V, the PCM sets this code. This could be an open or short to ground in the signal circuit. Or you may have lost the 5V reference.

Symptoms of a P2122 trouble code may include:

Symptoms may include:

  • Rough or low idle
  • stolling
  • Growing
  • No / slight acceleration
  • other symptoms may also be present

Causes

While there are several potential causes for a P2122 DTC to be set, it is likely that one of four components is faulty: the throttle position sensor, throttle actuator control motor, throttle position actuator, or pedal position sensor. If all four of these parts are in good working order, the cause may be damaged wiring, connectors, or grounding.

The P2122 code may mean that one or more of the following events have occurred:

  • TPS is not securely attached
  • TPS circuit: short to ground or other wire
  • Defective TPS
  • Damaged computer (PCM)

Possible Solutions to P2122

Here are some recommended troubleshooting and repair steps:

  • Thoroughly check the Throttle Position Sensor (TPS), wiring connector and wiring for breaks, etc. Repair or replace as necessary
  • Check the voltage at the TPS (see your vehicle's service manual for more information). If the voltage is too low, this indicates a problem. Replace if necessary.
  • In the event of a recent replacement, the TPS may need to be adjusted. On some vehicles, installation instructions require the TPS to be properly aligned or adjusted, refer to your workshop manual for details.
  • If there are no symptoms, the problem may be intermittent, and clearing the code may temporarily fix it. If so, then you should definitely check the wiring to make sure that it is not rubbing against anything, not grounded, etc. The code may return.

How does a mechanic diagnose a P2122 code?

To begin diagnosing the cause of DTC P2122, first check for its existence. A qualified technician can do this with a special scanning device that collects vehicle performance data and reports any anomalies in the form of trouble codes. OBD II. Once a mechanic performs a scan and a P2122 code is logged, further tests and/or checks are needed 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 fault code from the computer's memory and uses the specialized scanner again. If code P2122 does not register, the problem is most likely resolved. On the other hand, if the code registers again, additional diagnostic efforts will be required.

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

Once the repair is done, the mechanic will clear the OBD-II DTC, scan again for anomalies, and possibly test drive the vehicle to make sure the problem has been satisfactorily resolved.

Common Mistakes When Diagnosing Code P2122

After registering the P2122 code, mechanics sometimes make the following mistakes:

  • Inability to resolve fault codes in the order they appear when multiple codes are registered
  • Failed to check for code P2122
  • Unable to reset code P2122 from trip computer after repair

How serious is the P2122 code?

Although some vehicles do not go into a "won't start" condition after a P2122 DTC is logged, this does not mean that the problem that caused it should be ignored. Whether the root cause of the code being logged is a faulty component, a loose wire, or something else, failure to fix the problem can negatively impact other parts or systems. In the long run, this can lead to more costs and problems with repairs than with a quick fix.

What repairs can fix code P2122?

After a P2122 DTC entry is considered valid using a dedicated scan tool, the following actions may be required:

  • Replacing or moving the ground wire
  • Replacing Wiring and/or Connectors in CAN Bus Harness or Throttle Actuator Motor
  • Replacing the Throttle Position Sensor, Throttle Actuator Motor, Throttle Position Actuator or Pedal Position Sensor

Additional comments to consider regarding code P2122

When diagnosing code P2122, the process can take up to several hours. This is due to the potential need for several tests with a scanning device or voltage meter, manual checks and test drives. With a careful approach from the beginning, the likelihood of other related problems is greatly reduced.

P2122 Accelerator Pedal Position Sensor

Need more help with your p2122 code?

If you still need help with DTC P2122, post a question in the comments below this article.

NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.

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