P0785 Code: Shift Timing Solenoid “A” Malfunction

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on December 17th, 2024

Reading Time: 3 minutes
Summary
  • DTC P0785 stands for “Shift Timing Solenoid ‘A’ Malfunction.”
  • It is triggered when the PCM detects an electrical or mechanical issue in the shift timing solenoid or its circuit.
  • This code is usually logged due to a damaged timing shift solenoid, dirty or low levels of ATF, and damaged wiring.
  • Some of the most common symptoms associated with this code include erratic shifting, transmission slipping, and hard shifting.

Diagnosing code P0785 for the first time might be difficult. You’ll need to look at the underlying problems that have triggered this diagnostic trouble code. Keep reading to learn more about what this code means and how best to approach a solution.

What Does the P0785 Code Mean?

Code P0785 stands for “Shift Timing Solenoid ‘A’ Malfunction.” This generic powertrain code applies to vehicles with OBD-II, which includes most vehicles made 1996 onwards. 

Your check engine light might illuminate if your powertrain control module (PCM) detects an electrical or mechanical issue in the shift timing solenoid or its circuit. There are several shift timing solenoids in your system, which are controlled by the transmission control module (TCM). The letter “A” refers to a general malfunction in the “‘A” solenoid or circuit.

The shift timing solenoid is an integral component of your automatic transmission system. This solenoid is responsible for controlling the flow of hydraulic fluid in the system, so that you can smoothly shift your transmission. Any issues with the solenoid can affect your vehicle’s driveability.

For more technical information about codes like P0785, read our note about shift solenoids.

There are several shift timing solenoids in your vehicle controlled by the transmission control module.

Note: The definition of code P0785 may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition. If you have a GM vehicle that has a 4L60-E transmission, a P0785 code is defined as “Transmission 3-2 Shift Solenoid.”

What are the Possible Causes of the P0785 Code?

A P0785 might be triggered due to one or more factors. Here are some of the possible causes of a P0785 code.

  • Faulty or damaged shift timing solenoid
  • Dirty automatic transmission fluid (ATF)
  • Low ATF
  • Blocked ATF passages
  • Damaged wiring harness
  • TCM issue
  • PCM issue
  • Pin or connector problem
Dirty automatic transmission fluid can trigger the code P0785.

What are the Common Symptoms of the P0785  Code?

A P0497 code might be accompanied by other DTCs, so you might observe some symptoms not listed here. However, if your PCM is only storing a P0785, your vehicle might exhibit the following symptoms.

  • Erratic shifting
  • Transmission slipping
  • Hard shifting
  • Inefficient shift timing
  • Poor acceleration
  • Poor performance

How to Diagnose the P0785 Code

It isn’t easy to figure out the right fix for a P0785 code. Some of its underlying problems require specialized knowledge and skills in transmission repair. You can use the following video as a general reference for troubleshooting your P0785. However, you’ll still need to do some additional research on your vehicle before attempting any repairs. If you aren’t sure about your automotive repair skills, it’s best to consult a mechanic.

How to Fix the P0785 Code

There’s no single solution for troubleshooting a P0785 code. You’ll have to take your vehicle’s make and model into account in order to determine the possible issues that are triggering your DTC. What might work to resolve a P0785 code for a Chevy might not work for a Honda. There are vehicle-specific diagnostic and repair procedures you must follow to avoid expensive repairs down the line.

If you’re looking to repair your vehicle on your own, we suggest looking into ALLDATA’s single-vehicle subscription service to get detailed information, repair instructions, and part diagrams. You can also look up other credible OBD-II resources on the internet.

However, if you don’t have the time and patience to troubleshoot your P0785 code, you can also get a mechanic to do it for you. Automatic transmission systems have numerous components, which can fail over time. They can be difficult to diagnose and repair if you don’t have any previous automotive repair experience. Hiring a mechanic is probably the best choice for beginners.

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician