AutoCodes – GMC – P07BF 2018 GMC Sierra

P07BF 2018 GMC Sierra Code - Transmission Input Speed Sensor Circuit Low Voltage

Quick Answer

The Input Speed Sensor detects the primary pulley revolution speed and sends a signal to the Transmission. Common causes include Faulty Transmission Input Speed Sensor, Transmission Input Speed Sensor harness is open or shorted, Transmission Input 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: P07BF 2018 GMC Sierra indicates Transmission Input Speed Sensor Circuit Low Voltage.
Common causes: Common causes include Faulty Transmission Input Speed Sensor, Transmission Input Speed Sensor harness is open or shorted, Transmission Input 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 466

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 P07BF 2018 GMC Sierra Description

The Input Speed Sensor detects the primary pulley revolution speed and sends a signal to the Transmission. The Input Speed Sensor (ISS), also known as the transmission turbine speed sensor, is a hall-effect type sensor. The ISS mounts to the control valve upper body assembly and connects to the control solenoid (w/body and Transmission Control Module (TCM)) valve assembly through a wire harness and connector. The sensor faces the 1-2-3-4 and 3-5-R clutch housing machined teeth surface. The sensor receives 8.3-9.3 volts on the Input/Output Speed Sensor (ISS/OSS) supply voltage circuit from the Transmission Control Module (TCM). As the 1-2-3-4 and 3-5-R clutch housing rotates, the sensor produces a signal frequency based on the machined surface of the 1-2-3-4 and 3-5-R clutch housing. This signal is transmitted through the ISS signal circuit to the control solenoid (w/body and TCM) valve assembly. The control solenoid (w/body and TCM) valve assembly uses the ISS signal to determine line pressure, transmission shift patterns, Torque Converter Clutch (TCC) slip speed, and gear ratio. The Diagnostic Trouble Code (DTC) will be set when the TCM detects the ISS signal circuit voltage is less than 0.25 V for 0.8 s.

OBDII Code P07BF 2018 GMC Sierra - Transmission Input Speed Sensor Circuit Low Voltage - AutoCodes.com — P07BF 2018 GMC Sierra Code - Transmission Input Speed Sensor Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P07BF 2018 GMC Sierra?

Faulty Transmission Input Speed Sensor
Transmission Input Speed Sensor harness is open or shorted
Transmission Input Speed Sensor circuit poor electrical connection
Faulty Control Solenoid Valve Assembly

How to Fix the DTC P07BF 2018 GMC Sierra?

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 P07BF 2018 GMC Sierra 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 P07BF 2018 GMC Sierra code?

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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 P07BF 2018 GMC Sierra Code

What does the OBD-II code P07BF mean in a 2018 GMC Sierra?

The code P07BF indicates a "Transmission Input Speed Sensor Circuit Low Voltage," meaning the sensor is detecting an abnormally low voltage signal.

What are the common symptoms of code P07BF in a 2018 GMC Sierra?

Symptoms may include erratic or delayed shifting, poor acceleration, transmission slipping, and the Check Engine Light illuminated.

What causes the P07BF code in a 2018 GMC Sierra?

Causes can include a faulty input speed sensor, damaged wiring or connectors in the sensor circuit, or issues with the transmission control module (TCM).

How can I diagnose the P07BF code in my 2018 GMC Sierra?

You can diagnose the issue by inspecting the wiring and connectors for damage, testing the input speed sensor for proper function, and checking the voltage signal with a multimeter.

Can the P07BF code affect the transmission's performance?

Yes, this code can cause transmission shifting issues and affect overall drivability if not resolved promptly.

How do I fix the P07BF code in a 2018 GMC Sierra?

Repairs may involve replacing the input speed sensor, repairing damaged wiring or connectors, or reprogramming or replacing the transmission control module.

Can I drive my 2018 GMC Sierra with the P07BF code?

Driving with this code is not recommended as it can lead to further transmission damage and unsafe driving conditions.

How much does it cost to fix the P07BF code on a 2018 GMC Sierra?

Repair costs vary, but replacing the input speed sensor generally costs between $150-$300, while wiring repairs or TCM replacement may cost more.

Does the P07BF code require special tools to fix?

Basic tools like a multimeter, OBD-II scanner, and wiring repair equipment are often sufficient, but advanced diagnostics may require professional tools.

Can the P07BF code be cleared without repairing the issue?

Clearing the code without fixing the root cause is not advised, as the issue will likely return and could worsen over time.