AutoCodes – Mercedes-Benz – P0786 Mercedes-Benz

P0786 Mercedes-Benz Code - Shift/Timing Solenoid Range/Performance

Quick Answer

The 3-2 Shift Solenoid (SS) valve assembly is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty shifting solenoid valve. 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: P0786 Mercedes-Benz indicates Shift/Timing Solenoid Range/Performance.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty shifting solenoid valve.
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 2,240

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
FAQs
Comments
Add Comment

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

Code P0786 Mercedes-Benz Description

The 3-2 Shift Solenoid (SS) valve assembly is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. The solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage through circuit 239. The Powertrain Control Module (PCM) controls the solenoid by providing a ground path. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The PCM varies the timing between the 3-4 clutch release and the 2-4 band apply depending on the vehicle speed and the throttle position.
When the PCM detects a continuous open, short to ground or short to power in the 3-2 SS valve assembly circuit, then DTC P0786 sets.

OBDII Code P0786 Mercedes-Benz - Shift/Timing Solenoid Range/Performance - AutoCodes.com — P0786 Mercedes-Benz Code - Shift/Timing Solenoid Range/Performance

What does this mean?

What are the Possible Causes of the DTC P0786 Mercedes-Benz?

Low transmission fluid level
Dirty transmission fluid
Faulty shifting solenoid valve
Shifting solenoid valve harness is open or shorted
Shifting solenoid valve circuit poor electrical connection

How to Fix the DTC P0786 Mercedes-Benz?

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 P0786 Mercedes-Benz 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 P0786 Mercedes-Benz code?

Need more information on how to fix the P0786 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0786 Mercedes-Benz 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.

Frequently Asked Questions about P0786 Mercedes-Benz Code

1. What does the OBDII code P0786 mean on a Mercedes-Benz?

P0786 indicates an issue with the shift/timing solenoid, specifically related to its range or performance. This can affect gear shifting and transmission timing.

2. What are the common symptoms of code P0786 in a Mercedes-Benz?

Symptoms may include harsh or delayed shifting, erratic gear changes, transmission slipping, or the vehicle entering limp mode.

3. What causes the P0786 code in a Mercedes-Benz?

Common causes include a faulty shift solenoid, dirty or low transmission fluid, a damaged transmission valve body, or electrical issues such as corroded or damaged wiring.

4. Can I drive my Mercedes-Benz with a P0786 code?

Driving with a P0786 code is not recommended as it can lead to further transmission damage or unsafe driving conditions due to erratic gear shifts.

5. How do I diagnose the P0786 code in my Mercedes-Benz?

Diagnosis involves scanning for codes, inspecting transmission fluid condition and level, checking the shift solenoid's operation, and inspecting the wiring and connectors for damage.

6. How do I fix the P0786 code on my Mercedes-Benz?

Common fixes include replacing the faulty shift solenoid, cleaning or replacing the transmission fluid, repairing damaged wiring, or replacing the transmission valve body if necessary.

7. What tools are needed to fix the P0786 code?

You may need an OBDII scanner, basic hand tools, a multimeter for electrical testing, and potentially a transmission fluid pump for fluid replacement.

8. What is the cost of repairing the P0786 code on a Mercedes-Benz?

Repair costs can vary widely, ranging from $150 to $400 for a solenoid replacement to over $1,000 for more extensive transmission repairs.

9. Can low transmission fluid cause the P0786 code?

Yes, low or dirty transmission fluid can cause improper solenoid operation, leading to the P0786 code.

10. Is a software update ever required to fix the P0786 code?

In some cases, a transmission control module (TCM) software update may be necessary to resolve the issue, but this depends on the specific model and circumstances.