AutoCodes.com | All About OBDII Engine Codes
AutoCodes - Cadillac - P0121 Cadillac

P0121 Cadillac Code - Throttle Position Sensor 1 Performance

- Code Popularity: 51,442 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
Table of contents
Share on Facebook   Share on Twitter   Share on Linkedin

What are the Possible Causes of the DTC P0121 Cadillac?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Throttle Body Assembly
  • Throttle Body Assembly harness is open or shorted
  • Throttle Body Assembly circuit poor electrical connection
  • Faulty Engine Control Module (ECM)
⚠ Does your Cadillac have Safety Recalls? → Check here

How to Fix the DTC P0121 Cadillac?

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

Code Tech Notes

On most newer models, the Throttle Position Sensor (TPS) is part of the Throttle Body assembly. Replacing the Throttle Body should take care of the code.





User Submitted Video

Search for P0121 Cadillac Questions and Answers: Search here →

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. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

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

Need More Information on the 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

Code P0121 Cadillac comments

Help us improve AutoCodes.com. Leave a comment below or tell us if the information above helps you fix the code. What are the symptoms on your vehicle for the P0121 Cadillac code? Have you replaced any parts?
Any information is appreciated. Thanks