AutoCodes – Chevrolet – P077D Chevrolet

P077D Chevrolet Code - Transmission Output Speed Sensor Circuit High Voltage

Quick Answer

The Output Speed Sensor (OSS) is a hall-effect type sensor. Common causes include Faulty Transmission Output Speed Sensor (OSS), Transmission Output Speed Sensor harness is open or shorted, Transmission Output Speed 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: P077D Chevrolet indicates Transmission Output Speed Sensor Circuit High Voltage.
Common causes: Common causes include Faulty Transmission Output Speed Sensor (OSS), Transmission Output Speed Sensor harness is open or shorted, Transmission Output Speed 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.

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Code Popularity 1,068

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 Jul 29, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P077D Chevrolet Description

The Output Speed Sensor (OSS) is a hall-effect type sensor. The OSS mounts to the automatic transmission case assembly and connects to the control solenoid valve assembly through a 2-wire harness and connector. The sensor faces the park gear teeth. The sensor receives battery voltage on the OSS supply voltage circuit from the Transmission Control Module (TCM). As the output shaft rotates, the sensor produces a signal frequency based on the park gear teeth. This signal is transmitted through the OSS signal circuit to the TCM. The TCM uses the OSS signal to determine line pressure, transmission shift patterns, vehicle speed, and gear ratio.
The Diagnostic Trouble Code (DTC) will be set when the TCM detects the vehicle speed sensor signal circuit voltage is 4.75 V or greater for 0.8 s.

OBDII Code P077D Chevrolet - Transmission Output Speed Sensor Circuit High Voltage - AutoCodes.com — P077D Chevrolet Code - Transmission Output Speed Sensor Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P077D Chevrolet?

Faulty Transmission Output Speed Sensor (OSS)
Transmission Output Speed Sensor harness is open or shorted
Transmission Output Speed Sensor circuit poor electrical connection
Faulty Transmission Control Module (TCM)

How to Fix the DTC P077D Chevrolet?

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 P077D Chevrolet 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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Information for Specific Chevrolet Models

P077D 2014 Chevrolet Silverado — Transmission Output Speed Sensor Circuit High Voltage
P077D 2015 Chevrolet Silverado — Transmission Output Speed Sensor Circuit High Voltage
P077D 2016 Chevrolet Silverado — Transmission Output Speed Sensor Circuit High Voltage
P077D 2017 Chevrolet Silverado — Transmission Output Speed Sensor Circuit High Voltage
P077D 2018 Chevrolet Silverado — Transmission Output Speed Sensor Circuit High Voltage

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 P077D Chevrolet Code

1. What are the common symptoms of OBDII code P077D in a Chevrolet related to the Transmission Output Speed Sensor Circuit High Voltage?

- Common symptoms include erratic shifting, harsh shifting, transmission slippage, and the transmission going into limp mode.

2. What are the possible causes of OBDII code P077D in a Chevrolet related to the Transmission Output Speed Sensor Circuit High Voltage?

- Possible causes include a faulty output speed sensor, damaged wiring or connectors in the circuit, a malfunctioning transmission control module, or internal transmission issues.

3. How can I diagnose the OBDII code P077D in a Chevrolet related to the Transmission Output Speed Sensor Circuit High Voltage?

- Diagnosis usually involves using a scan tool to read the code, checking the output speed sensor for proper operation, inspecting the wiring and connectors for damage, and testing the transmission control module.

4. Can I continue to drive my Chevrolet with OBDII code P077D related to the Transmission Output Speed Sensor Circuit High Voltage?

- It is not recommended to continue driving the vehicle with this code present, as it can lead to further transmission damage and unsafe driving conditions.

5. How can I repair OBDII code P077D in a Chevrolet related to the Transmission Output Speed Sensor Circuit High Voltage?

- Repair options include replacing the faulty output speed sensor, repairing any damaged wiring or connectors, resetting the code, and testing the transmission for proper operation.

6. Are there any DIY tips for fixing OBDII code P077D in a Chevrolet related to the Transmission Output Speed Sensor Circuit High Voltage?

- While some basic troubleshooting and inspections can be done by DIY enthusiasts, repairing this code often requires specialized tools and expertise, so it is recommended to consult a professional mechanic.

7. What is the cost to repair OBDII code P077D in a Chevrolet related to the Transmission Output Speed Sensor Circuit High Voltage?

- The cost of repair can vary depending on the exact cause of the issue, but it may involve parts and labor costs ranging from $200 to $500 or more, depending on the extent of the repairs needed.

8. Can resetting the OBDII code P077D in a Chevrolet related to the Transmission Output Speed Sensor Circuit High Voltage fix the issue?

- Resetting the code may temporarily clear the warning light, but it will not address the underlying problem causing the code to trigger. It is important to diagnose and repair the issue to prevent further damage.

9. How long does it take to repair OBDII code P077D in a Chevrolet related to the Transmission Output Speed Sensor Circuit High Voltage?

- The repair time can vary depending on the specific cause of the issue, but it typically takes a few hours to a full day for a professional mechanic to diagnose and repair the problem.

10. Are there any recalls or technical service bulletins related to OBDII code P077D in a Chevrolet related to the Transmission Output Speed Sensor Circuit High Voltage?

- It's recommended to check with Chevrolet dealerships or online resources for any recalls or technical service bulletins related to this specific OBDII code to see if there are any known issues or solutions provided by the manufacturer.