AutoCodes – Generic – P078B

P078B Code - Shift Timing Solenoid 'B' Range/Performance

Quick Answer

The Transmission Control Module (TCM) monitors the Shift Timing Solenoid 'B' circuit. Common causes include Faulty Shift Timing Solenoid 'B', Shift Timing Solenoid 'B' harness is open or shorted, Shift Timing Solenoid 'B' 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: P078B indicates Shift Timing Solenoid 'B' Range/Performance.
Common causes: Common causes include Faulty Shift Timing Solenoid 'B', Shift Timing Solenoid 'B' harness is open or shorted, Shift Timing Solenoid 'B' 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 1,712

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 May 08, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P078B Description

The Transmission Control Module (TCM) monitors the Shift Timing Solenoid 'B' circuit. The TCM sets the OBDII code when the Shift Timing Solenoid 'B' is out of factory specifications.

OBDII Code P078B - Shift Timing Solenoid 'B' Range/Performance - AutoCodes.com — P078B Code - Shift Timing Solenoid 'B' Range/Performance

What does this mean?

What are the Possible Causes of the DTC P078B?

Faulty Shift Timing Solenoid 'B'
Shift Timing Solenoid 'B' harness is open or shorted
Shift Timing Solenoid 'B' circuit poor electrical connection

How to Fix the DTC P078B?

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 P078B 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 P078B code?

Need more information on how to fix the P078B code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P078B code diagnosed by a professional: Find a repair shop in your area

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.