AutoCodes – Honda – P0121 Honda

P0121 Honda Code - Throttle Position Sensor 'A' Out of Range

Quick Answer

The electronic throttle control system controls the throttle valve opening. Common causes include Faulty Throttle Body, Throttle Body harness is open or shorted, Throttle Body 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: P0121 Honda indicates Throttle Position Sensor 'A' Out of Range.
Common causes: Common causes include Faulty Throttle Body, Throttle Body harness is open or shorted, Throttle Body 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 529

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 02, 2023

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code P0121 Honda Description

The electronic throttle control system controls the throttle valve opening. The system includes the throttle actuator, the throttle valve, Throttle Position (TP) sensors 'A' and 'B', the Electronic Throttle Control System (ETCS) control relay, the Accelerator Pedal Position (APP) sensor, and the Powertrain Control Module (PCM). TP Sensor 'A' is a semiconductor type, and it is attached to the throttle body and shaft to determine the throttle valve position. The throttle valve position signal from TP Sensor 'A' is transmitted to the PCM for target position feedback control. If the signal from TP Sensor 'A' is a fixed value for a set time, the PCM detects a TP Sensor 'A' malfunction and stores a Diagnostic Trouble Code (DTC).

OBDII Code P0121 Honda - Throttle Position Sensor 'A' Out of Range - AutoCodes.com — P0121 Honda Code - Throttle Position Sensor 'A' Out of Range

What does this mean?

What are the Possible Causes of the DTC P0121 Honda?

Faulty Throttle Body
Throttle Body harness is open or shorted
Throttle Body circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC P0121 Honda?

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 does this mean?

Code Tech Notes

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0121 Honda 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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Need more information on how to fix the P0121 Honda code? Get Access to Factory Service Manuals

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Information for Specific Honda Models

P0121 2016 Honda CR-V — Throttle Position Sensor 'A' Out of Range
P0121 2017 Honda CR-V — Throttle Position Sensor 'A' Out of Range
P0121 2018 Honda CR-V — Throttle Position Sensor 'A' Out of Range
P0121 2019 Honda CR-V — Throttle Position Sensor 'A' Out of Range
P0121 2020 Honda CR-V — Throttle Position Sensor 'A' Out of Range
P0121 2021 Honda CR-V — Throttle Position Sensor 'A' Out of Range

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 P0121 Honda Code

What does OBDII code P0121 mean for a Honda?

P0121 indicates that the throttle position sensor (TPS) 'A' is reporting a voltage signal that is out of the expected range, suggesting a possible issue with the sensor or related systems.

What are the common symptoms of code P0121 on a Honda?

Symptoms may include poor acceleration, hesitation, stalling, reduced fuel efficiency, an illuminated check engine light, or entering limp mode.

What causes the P0121 code to appear?

Common causes include a faulty throttle position sensor, damaged wiring or connectors, a dirty or malfunctioning throttle body, or issues with the engine control module (ECM).

Can a dirty throttle body trigger the P0121 code?

Yes, carbon buildup on the throttle body can interfere with the throttle position sensorâ€™s readings, potentially triggering the P0121 code.

How do I diagnose the P0121 code on a Honda?

Start by inspecting the TPS wiring and connectors for damage, check for throttle body cleanliness, and use a scan tool to monitor TPS voltage readings for abnormalities.

Can I drive my Honda with a P0121 code?

You can drive short distances, but itâ€™s not recommended, as the vehicle may experience performance issues like stalling or limp mode, which could compromise safety.

How do you fix the P0121 code?

Repairs may involve cleaning the throttle body, replacing the throttle position sensor, repairing faulty wiring, or updating/reprogramming the ECM if necessary.

Does the P0121 code always mean the throttle position sensor is bad?

No, the issue could also stem from wiring problems, a dirty throttle body, or other related components.

How much does it cost to fix the P0121 code on a Honda?

The repair cost varies, but replacing a throttle position sensor typically ranges from $100 to $300, including parts and labor. Additional repairs may increase the cost.

Can a faulty TPS cause long-term damage if ignored?

Yes, ignoring a faulty TPS can lead to poor engine performance, increased fuel consumption, and potential damage to other engine components over time.