P1121 GMC Code - Throttle Position Sensor Circuit Intermittent High Voltage
Quick Answer
The Throttle Position (TP) sensor is a potentiometer. Common causes include Faulty Throttle Position Sensor, Throttle Position Sensor harness is open or shorted, Throttle Position 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
- P1121 GMC indicates Throttle Position Sensor Circuit Intermittent High Voltage.
- Common causes
- Common causes include Faulty Throttle Position Sensor, Throttle Position Sensor harness is open or shorted, Throttle Position 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.
Code P1121 GMC Description
TP sensor Signal voltage should be about 0.6 volt at idle. The TP sensor voltage should increase to above 4.0 volts at wide open throttle (WOT).
What are the Possible Causes of the DTC P1121 GMC?
- Faulty Throttle Position Sensor
- Throttle Position Sensor harness is open or shorted
- Throttle Position Sensor circuit poor electrical connection
- Throttle Position Sensor not properly adjusted
How to Fix the DTC P1121 GMC?
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 P1121 GMC 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 P1121 GMC code?
Need more information on how to fix the P1121 GMC code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P1121 GMC code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P1121 GMC Code
1. What are the common symptoms of OBDII code P1121 in a GMC vehicle?
The common symptoms of OBDII code P1121 include rough idling, reduced engine power, hesitation or surging during acceleration, and illuminated Check Engine light.
2. What are the possible causes of the Throttle Position Sensor Circuit Intermittent High Voltage code (P1121) in a GMC?
Possible causes of P1121 in a GMC include a faulty throttle position sensor, damaged wiring or connectors in the throttle position sensor circuit, or issues with the powertrain control module (PCM).
3. How can I diagnose the Throttle Position Sensor Circuit Intermittent High Voltage code (P1121) in my GMC?
Diagnosing P1121 involves using an OBDII scanner to retrieve the code, checking the throttle position sensor's voltage readings, inspecting the sensor's wiring and connections, and testing the PCM for any faults.
4. Can I continue driving my GMC with OBDII code P1121 present?
It is not recommended to continue driving your GMC with OBDII code P1121 present, as it can lead to poor engine performance, reduced fuel efficiency, and potential further damage to the vehicle's components.
5. How can I repair OBDII code P1121 in my GMC?
Repairing P1121 may involve replacing the throttle position sensor, repairing or replacing damaged wiring and connectors, or reprogramming the PCM. It is recommended to consult a professional mechanic for an accurate diagnosis and repair.
6. Will resetting the Check Engine light fix OBDII code P1121 in my GMC?
Simply resetting the Check Engine light will not fix OBDII code P1121. The underlying issue causing the code must be diagnosed and repaired to prevent the code from reoccurring.
7. How much does it typically cost to repair OBDII code P1121 in a GMC?
The cost of repairing OBDII code P1121 in a GMC can vary depending on the cause of the issue, the required parts, and the labor rates of the repair shop. It is advisable to obtain quotes from multiple mechanics or dealerships.
8. Can a DIY enthusiast repair OBDII code P1121 in a GMC?
While some DIY enthusiasts may have the skills to diagnose and repair OBDII code P1121, it is a complex issue that may require specialized tools and knowledge. If you are unsure, it is recommended to seek professional help.
9. How long does it take to repair OBDII code P1121 in a GMC?
The time required to repair OBDII code P1121 in a GMC can vary depending on the specific cause of the issue, the availability of parts, and the expertise of the mechanic. It is best to consult with the repair shop for a more accurate estimate.
10. Is OBDII code P1121 a common issue in GMC vehicles?
While OBDII code P1121 (Throttle Position Sensor Circuit Intermittent High Voltage) is not as common as some other codes, it can still occur in GMC vehicles, particularly in older models or those with high mileage.
Discuss the causes and fixes for P1121 GMC OBDII Code
Code P1121 GMC comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
