P077D GMC Code - Transmission Output Speed Sensor Circuit High Voltage
Quick Answer
The P077D GMC code indicates a problem with the transmission output speed sensor circuit, specifically detecting high voltage. Common causes include Faulty transmission output speed sensor, Wiring issues or shorts in the sensor circuit, Corrosion or poor connections in the sensor circuit. 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
- P077D GMC indicates Transmission Output Speed Sensor Circuit High Voltage.
- Common causes
- Common causes include Faulty transmission output speed sensor, Wiring issues or shorts in the sensor circuit, Corrosion or poor connections in the sensor circuit.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P077D GMC Description
The P077D GMC code indicates a problem with the transmission output speed sensor circuit, specifically detecting high voltage. The transmission output speed sensor is responsible for monitoring the speed of the output shaft of the transmission. This information is crucial for the vehicle's transmission control module to determine shift points and ensure smooth gear changes. When the sensor detects high voltage, it means that the signal being sent to the transmission control module is outside of the normal operating range. This can lead to issues with shifting, fuel efficiency, and overall drivability of the vehicle.
Common Causes of P077D GMC
- Faulty transmission output speed sensor
- Wiring issues or shorts in the sensor circuit
- Corrosion or poor connections in the sensor circuit
- Issues with the transmission control module
- Electrical problems in the vehicle's system
Symptoms of P077D GMC
- Erratic shifting or harsh shifting
- Delayed or prolonged shifting between gears
- Transmission slipping
- Decreased fuel efficiency
- Illumination of the Check Engine Light
How to Fix P077D GMC
- Begin by diagnosing the specific cause of the high voltage in the transmission output speed sensor circuit using a scan tool to retrieve the trouble codes and perform a visual inspection of the sensor and wiring.
- Test the transmission output speed sensor using a multimeter to check for proper resistance and voltage output.
- Inspect the wiring harness for any damage, corrosion, or loose connections. Repair or replace any damaged wiring as needed.
- If the sensor is faulty, replace it with a new one following the manufacturer's recommendations and reset the trouble codes.
- Clear the codes, test drive the vehicle to ensure the issue has been resolved, and recheck for any remaining trouble codes.
Cost to Fix P077D GMC
The typical repair costs for addressing a transmission output speed sensor circuit high voltage issue can range from $150 to $400, including parts and labor. However, the specific diagnosis time and labor rates at auto repair shops can vary based on factors such as location, vehicle make and model, and engine type. It's recommended to check with local auto repair shops for a more accurate estimate based on your specific circumstances. Keep in mind that rates at dealerships or in metropolitan areas may be higher, while independent shops often offer more competitive pricing.
Need more information about the P077D GMC code?
Need more information on how to fix the P077D GMC code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P077D GMC code diagnosed by a professional: Find a repair shop in your area
Information for Specific GMC Models
- P077D 2014 GMC Sierra — Transmission Output Speed Sensor Circuit High Voltage
- P077D 2015 GMC Sierra — Transmission Output Speed Sensor Circuit High Voltage
- P077D 2016 GMC Sierra — Transmission Output Speed Sensor Circuit High Voltage
- P077D 2017 GMC Sierra — Transmission Output Speed Sensor Circuit High Voltage
- P077D 2018 GMC Sierra — Transmission Output Speed Sensor Circuit High Voltage
Frequently Asked Questions about P077D GMC Code
1. What are the common symptoms of OBDII code P077D GMC (Transmission Output Speed Sensor Circuit High Voltage)?
- Common symptoms include erratic shifting behavior, transmission slipping, and the transmission going into limp mode.
2. What are the possible causes of OBDII code P077D GMC?
- The code P077D GMC may be caused by a faulty transmission output speed sensor, damaged wiring or connectors in the sensor circuit, or issues with the transmission control module.
3. How can I diagnose the cause of OBDII code P077D GMC?
- You can diagnose the cause of the code by performing a visual inspection of the sensor and its wiring, conducting a multimeter test to check for proper sensor operation, and using a scan tool to retrieve and interpret the code.
4. What is the potential risk of driving with OBDII code P077D GMC active?
- Driving with the P077D code active may lead to further damage to the transmission and other drivetrain components. It is recommended to address the issue promptly to prevent costly repairs.
5. Can I repair OBDII code P077D GMC myself?
- Depending on your experience level and access to tools, you may be able to repair the issue causing the code. However, it is recommended to consult a professional mechanic for accurate diagnosis and proper repair.
6. How much does it typically cost to repair OBDII code P077D GMC?
- The cost of repairing the P077D code can vary depending on the underlying cause. Costs may range from $100 to $500, including parts and labor.
7. Are there any DIY tips to troubleshoot OBDII code P077D GMC before seeking professional help?
- You can start by checking the sensor and its wiring for visible damage, ensuring proper connections, and clearing the code to see if it reappears after driving. If the issue persists, it's best to consult a mechanic.
8. What steps should I take if OBDII code P077D GMC keeps coming back after repair attempts?
- If the code keeps reappearing after repair attempts, it may indicate an intermittent issue or a deeper underlying problem. In such cases, it is advisable to seek professional diagnostic assistance.
9. Can a faulty transmission output speed sensor cause other transmission issues besides triggering OBDII code P077D GMC?
- Yes, a faulty sensor can cause a range of transmission issues, including rough shifting, delayed engagement, and even complete transmission failure if not addressed promptly.
10. Is it safe to continue driving my vehicle with OBDII code P077D GMC if the transmission seems to be operating normally?
- While the transmission may seem to be operating normally, it's important to address the underlying issue causing the code to prevent potential transmission damage in the future. It is recommended to have the problem diagnosed and repaired as soon as possible.
Discuss the causes and fixes for P077D GMC OBDII Code
Code P077D 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.