AutoCodesCadillac – P0121 Cadillac

P0121 Cadillac Code - Throttle Position Sensor 1 Performance

Quick Answer

The Throttle Body Assembly contains a contact-less inductive throttle position sensing element that is managed by a customized integrated circuit. Common causes include Faulty Throttle Body Assembly, Throttle Body Assembly harness is open or shorted, Throttle Body Assembly 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 Cadillac indicates Throttle Position Sensor 1 Performance.
Common causes
Common causes include Faulty Throttle Body Assembly, Throttle Body Assembly harness is open or shorted, Throttle Body Assembly 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.
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 52,605
How popular is this code, among other codes? Medium
Table of contents Created and updated by William Orellana on May 20, 2022
💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0121 Cadillac Description

The Throttle Body Assembly contains a contact-less inductive throttle position sensing element that is managed by a customized integrated circuit. The throttle position sensor is mounted within the throttle body assembly and is not serviceable. The Engine Control Module (ECM) supplies the throttle body with a 5 V reference circuit, a low reference circuit. The asynchronous signal means communication is only going from the throttle body to the ECM. The throttle body cannot receive data from the ECM over the signal/serial data circuit. The throttle position sensor provides a signal voltage that changes relative to throttle blade angle. The throttle position sensor information is transmitted between the throttle body and the ECM on the signal/serial data circuit. The ECM decodes the serial data signal and is used as voltages for throttle position sensor 1 and 2. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the throttle position sensor 1 voltage is stuck in range for greater than 1 s.
OBDII Code P0121 Cadillac - Throttle Position Sensor 1 Performance - AutoCodes.com
P0121 Cadillac Code - Throttle Position Sensor 1 Performance

What are the Possible Causes of the DTC P0121 Cadillac?

  • Faulty Throttle Body Assembly
  • Throttle Body Assembly harness is open or shorted
  • Throttle Body Assembly circuit poor electrical connection
  • Faulty Engine Control Module (ECM)

How to Fix the DTC P0121 Cadillac?

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.

Code Tech Notes

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0121 Cadillac 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.

Need more information about the P0121 Cadillac code?

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

Need Help with the Code?

Get the P0121 Cadillac code diagnosed by a professional: Find a repair shop in your area

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 Cadillac Code

1. What are the common symptoms of OBDII code P0121 in a Cadillac related to the throttle position sensor?

- Common symptoms include rough idling, poor acceleration, stalling, and potential issues with shifting gears.

2. What are the possible causes of the P0121 code in a Cadillac indicating throttle position sensor performance issues?

- The code may be triggered by a faulty throttle position sensor, wiring issues, a dirty throttle body, or a problem with the engine control module (ECM).

3. How can I diagnose the source of the P0121 code in my Cadillac related to the throttle position sensor?

- Diagnose the issue by checking the throttle position sensor's wiring and connections, inspecting the sensor itself for damage, and testing the sensor's voltage output.

4. Can I drive my Cadillac with the P0121 code indicating throttle position sensor performance problems?

- It is not recommended to drive your Cadillac with the P0121 code active, as it can lead to poor performance and potential safety hazards.

5. Is it possible to repair the P0121 code in a Cadillac related to the throttle position sensor without professional help?

- Depending on your level of automotive knowledge, you may be able to replace the throttle position sensor yourself, but it's recommended to consult a professional for accurate diagnosis and repair.

6. How much does it typically cost to repair the P0121 code related to the throttle position sensor in a Cadillac?

- The cost of repairing the P0121 code can vary depending on the root cause, but expenses may include parts like a new throttle position sensor and labor costs for installation.

7. What are some preventive maintenance tips to avoid encountering the P0121 code in a Cadillac?

- Regularly cleaning the throttle body, inspecting the throttle position sensor for wear, and addressing any unusual engine performance issues promptly can help prevent the P0121 code.

8. Can a faulty throttle position sensor causing the P0121 code affect the fuel efficiency of my Cadillac?

- Yes, a malfunctioning throttle position sensor can lead to poor fuel efficiency due to incorrect fuel-to-air ratios and engine performance issues.

9. Will resetting the OBDII system clear the P0121 code related to the throttle position sensor in a Cadillac?

- Resetting the OBDII system may temporarily clear the code, but if the underlying issue with the throttle position sensor is not fixed, the code is likely to return.

10. Is the P0121 code indicating throttle position sensor performance a common issue in Cadillacs?

- Throttle position sensor performance problems leading to the P0121 code can occur in Cadillac vehicles, especially in older models or those with high mileage.

Discuss the causes and fixes for P0121 Cadillac OBDII Code

  • Where is the tps on a 2006 Cadillac dts

  • The TPS is part of the throttle body. You can't replace the TPS by itself, you have to replace the Throttle Body Assembly.

  • I facing a problem with my cadillac srx 2006 since 4 months, engine warning light is on and sometimes flashing, So engine is shaking and the power is reduced. had changed the coil but the problem stil there. I'll give it a try and change the Throttle Position Sensor.

  • I'm having a very similar issue and Autozone states my TPS is bad. Where is it located on a '00 Cadillac STS? Thanks, any help is appreciated.

  • The "Throttle Position" (TP) Sensor is attached to the throttle body. The throttle body is on top of the engine.

  • Is the TPS for a 2007 Cadillac Escalade ESV part of the whole throttle body assembly?

  • Yes. On you 2007 Cadillac Escalade the TPS is part of the throttle body.

  • I have 2007 cadillac DTS ..code p0121...can i replace Trottle senser with scanner if i get the program codes

  • For your 2007 DTS, the Throttle Position Sensor is part of the Throttle body. You have to replace the Throttle Body Assembly

    Image

    Click here to enlarge image

  • i have a 2004 Cadillac cts and i cant find the TPS at all

  • The TPS it's built inside the throttle body.

    Image

    Click here to enlarge image

  • iam having the same problem in my( cadillac dts 4.6 2006 ).and i replaced the throttle but the problem stayed.what would be the problem then?

  • The next step is to have your local dealer reprogram the Powertrain Control Module (PCM) with the latest software.

  • I have a 2007 Escalade and replaced the throttle body but the code still comes up. What would be the next step?

  • Did you used a new factory Throttle Body? if you did, then you could try reprogramming the Powertrain Control Module (PCM). Other than the Throttle Body, there are no other components listed that could set the P0121 code.

AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play