AutoCodes – Generic – P2123

P2123 Code - Throttle/Pedal Position Sensor/Switch 'D' Circuit High

Quick Answer

The Accelerator Pedal Position (APP) sensor is an input to the Powertrain Control Module (PCM) and used to determine the amount of torque requested by the operator. Common causes include Faulty Accelerator Pedal Position (APP) Sensor, Accelerator Pedal Position (APP) Sensor harness is open or shorted, Accelerator Pedal Position (APP) Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P2123 indicates Throttle/Pedal Position Sensor/Switch 'D' Circuit High.
Common causes: Common causes include Faulty Accelerator Pedal Position (APP) Sensor, Accelerator Pedal Position (APP) Sensor harness is open or shorted, Accelerator Pedal Position (APP) Sensor circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 29,665

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2123 Description

The Accelerator Pedal Position (APP) sensor is an input to the Powertrain Control Module (PCM) and used to determine the amount of torque requested by the operator. There are 2 pedal position signals in the sensor. Both signals, APP and APP2, have a positive slope (increasing angle, increasing voltage), but are offset and increase at different rates. The 2 pedal position signals make sure the PCM receives a correct input even if 1 signal has a concern. The PCM determines if a signal is incorrect by calculating where it should be, inferred from the other signals. If a concern is present with one of the circuits the other input is used. There are 2 reference voltage circuits, 2 signal return circuits, and 2 signal circuits (a total of 6 circuits and pins) between the PCM and the APP sensor assembly. The pedal position signal is converted to pedal travel degrees (rotary angle) by the PCM. The software converts these degrees to counts, which is the input to the torque based strategy.

OBDII Code P2123 - Throttle/Pedal Position Sensor/Switch 'D' Circuit High - AutoCodes.com — P2123 Code - Throttle/Pedal Position Sensor/Switch 'D' Circuit High

What does this mean?

What are the Possible Causes of the DTC P2123?

Faulty Accelerator Pedal Position (APP) Sensor
Accelerator Pedal Position (APP) Sensor harness is open or shorted
Accelerator Pedal Position (APP) Sensor circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC P2123?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2123 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Makes

P2123 Acura — Accelerator Pedal Position Sensor 'A' Throttle Position Sensor 'D' Circuit High Voltage
P2123 BMW — Throttle/Pedal Positio Sensor/Switch 'D' Circuit High
P2123 Buick — Accelerator Pedal Position Sensor 1 Circuit High Voltage
P2123 Cadillac — Accelerator Pedal Position Sensor 1 Circuit High Voltage
P2123 Chevrolet — Accelerator Pedal Position Sensor 1 Circuit High Voltage
P2123 Dodge — Throttle Actuator Ctrl Motor Current Range/Perf
P2123 Ford — Throttle/Pedal Position Sensor/Switch 'D' Circuit High
P2123 GMC — Accelerator Pedal Position Sensor 1 Circuit High Voltage
P2123 Honda — Accelerator Pedal Position Sensor 'A' Throttle Position Sensor 'D' Circuit High Voltage
P2123 Hyundai — Accelerator Position Circuit - High Input
P2123 Infiniti — Accelerator Pedal Position Sensor Circuit Range/Performance
P2123 Lexus — Throttle Pedal Position Sensor/Switch 'D' Circuit Input High
P2123 Lincoln — Throttle/Pedal Position Sensor/Switch 'D' Circuit High
P2123 Mercedes-Benz — Throttle/Pedal Position Sensor/Switch 'D' Circuit High
P2123 Mercury — Throttle/Pedal Position Sensor/Switch 'D' Circuit High
P2123 MINI — Throttle/Pedal Positio Sensor/Switch 'D' Circuit High
P2123 Nissan — Accelerator Pedal Position Sensor Circuit Range/Performance
P2123 Scion — Throttle Pedal Position Sensor/Switch 'D' Circuit Input High
P2123 Toyota — Throttle Pedal Position Sensor/Switch 'D' Circuit Input High

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P2123 Code

1. What are common symptoms of OBDII code P2123?

- Common symptoms include reduced engine power, hesitation or stalling when accelerating, and the vehicle going into limp mode.

2. What can cause OBDII code P2123 to trigger?

- The code P2123 is typically triggered by a fault in the throttle/pedal position sensor 'D' circuit, which can be caused by a faulty sensor, damaged wiring, or a poor connection.

3. How serious is OBDII code P2123?

- OBDII code P2123 should be addressed promptly as it can lead to unsafe driving conditions and potential engine damage if left unresolved.

4. What are the possible repair options for OBDII code P2123?

- Repair options include replacing the throttle position sensor, repairing damaged wiring or connections, or resetting the sensor calibration.

5. Can I drive my vehicle with OBDII code P2123?

- It is not recommended to drive your vehicle with OBDII code P2123 as it can lead to unexpected loss of power or control while driving.

6. How can I diagnose OBDII code P2123?

- Diagnosing OBDII code P2123 involves using a scan tool to read the code and performing tests on the throttle position sensor and its circuit to identify the root cause.

7. Is it safe to reset the OBDII code P2123 without fixing the underlying issue?

- Resetting the code without fixing the underlying issue is not recommended, as the problem will likely resurface, potentially causing further damage to the vehicle.

8. How much does it cost to fix OBDII code P2123?

- The cost to fix OBDII code P2123 can vary depending on the cause of the issue, but it typically involves replacing the throttle position sensor, which can range from $100 to $300 including labor.

9. Can a DIY enthusiast fix OBDII code P2123 at home?

- DIY enthusiasts with the necessary tools and knowledge may be able to fix OBDII code P2123 at home by following repair guides or tutorials specific to their vehicle make and model.

10. Will OBDII code P2123 cause permanent damage to my vehicle if not addressed immediately?

- Ignoring OBDII code P2123 can lead to performance issues and potential damage to the engine over time, so it is best to address the issue promptly to prevent further complications.