AutoCodes – Subaru – P0766 Subaru

P0766 Subaru Code - Shift Solenoid 'D' Performance or Stuck Off

Quick Answer

Shift solenoid valve 'D' is turned ON or OFF by the Transmission Control Module (TCM) in response to signals sent from the park/neutral position (PNP) switch, vehicle speed and Engine Control Module (ECM) (throttle opening). Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty shift solenoid 'D' 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: P0766 Subaru indicates Shift Solenoid 'D' Performance or Stuck Off.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty shift solenoid 'D' 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.

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Code Popularity 7,241

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 Jun 14, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0766 Subaru Description

OBDII Code P0766 Subaru - Shift Solenoid 'D' Performance or Stuck Off - AutoCodes.com — P0766 Subaru Code - Shift Solenoid 'D' Performance or Stuck Off

What does this mean?

What are the Possible Causes of the DTC P0766 Subaru?

Low transmission fluid level
Dirty transmission fluid
Faulty shift solenoid 'D' valve
Shift solenoid 'D' valve harness or connectors
Shift solenoid 'D' valve circuit is open or shorted

How to Fix the DTC P0766 Subaru?

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 does this mean?

Code Tech Notes

When the a transmission solenoid is stuck off, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is very dirty, it is recommend changing the transmission fluid and if possible removing the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a transmission mechanical failure and that the transmission will need to be rebuilt or replaced.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0766 Subaru 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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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 P0766 Subaru Code

1. What are some common symptoms of OBDII code P0766 in a Subaru?

- Common symptoms include harsh shifting, delayed shifting, transmission slipping, and the transmission sticking in a particular gear.

2. What could cause the Shift Solenoid 'D' Performance or Stuck Off code in a Subaru?

- Possible causes of P0766 in a Subaru include a faulty shift solenoid 'D', low transmission fluid levels, a clogged transmission filter, or wiring issues.

3. How serious is OBDII code P0766 in a Subaru?

- OBDII code P0766 should be addressed promptly to prevent further damage to the transmission. Ignoring this code can lead to more severe transmission issues over time.

4. Can I continue driving my Subaru with the P0766 code present?

- It is not recommended to continue driving your Subaru with the P0766 code present, as it can cause damage to the transmission and potentially leave you stranded.

5. How can I diagnose the Shift Solenoid 'D' Performance or Stuck Off code in my Subaru?

- Diagnosing P0766 typically involves using a scan tool to read the code, checking the transmission fluid level and condition, and inspecting the shift solenoid 'D' and its wiring for any visible issues.

6. Is it possible to repair OBDII code P0766 in a Subaru without professional help?

- While some DIY enthusiasts may be able to replace a faulty shift solenoid 'D' themselves, diagnosing and repairing the underlying cause of P0766 may require professional expertise and specialized tools.

7. How much does it cost to fix the Shift Solenoid 'D' Performance or Stuck Off code in a Subaru?

- The cost of fixing P0766 in a Subaru can vary depending on the root cause of the issue, the extent of the repairs needed, and whether you choose to do the work yourself or seek professional help.

8. Can a simple transmission fluid change resolve OBDII code P0766 in a Subaru?

- In some cases, performing a transmission fluid change and ensuring the correct fluid level may help resolve the P0766 code, especially if the issue was caused by low fluid levels or contamination.

9. Are there any preventive maintenance tips to avoid encountering the P0766 code in a Subaru?

- Regularly checking and maintaining proper transmission fluid levels, changing the transmission fluid at recommended intervals, and addressing any transmission-related symptoms promptly can help prevent OBDII code P0766 in a Subaru.

10. Is it safe to reset the OBDII code P0766 in a Subaru without fixing the underlying issue?

- While you can clear the code temporarily, it is not recommended to reset P0766 without addressing the root cause, as the issue may resurface and potentially lead to more severe transmission problems.