P0766 on Subaru: How to Diagnose & Fix
Shift Solenoid D Performance/Stuck Off
1 Subaru model · 1 documented issue · $150-$1,500 repair
P0766 on Subaru by model: symptoms, diagnosis and fix
Subaru Service Bulletin 16-86-12 (12/11/2012) covers 2013 Tribecas with the EZ36D and 5-speed automatic, along with the 2013 Legacy and Outback. On these vehicles the AT OIL TEMP lamp comes on with one or more stored solenoid and pressure-control DTCs: P0751, P0756, P0761, P0766, P0771 or P1840-P1844. Subaru traced it to TCM logic. The fix went into production in mid-November 2012 starting at Tribeca VIN D*400781. Earlier 2013 Tribecas with TCM part numbers 30919AB190/191/192 are affected. The bulletin's applicability is written for low-mileage vehicles (6,000 miles or less). This lamp is separate from the torque-converter shudder that is already cataloged.
Common Symptoms
- AT OIL TEMP lamp on or flashing on the dash
- Stored transmission solenoid DTCs
How to Fix
Have a Subaru technician check the current bulletin and calibration. TSB 16-86-12 is expressly limited to low-mileage (6,000 miles or less) 2013 5AT vehicles with the listed codes. For an applicable Tribeca, it specifies TCM calibration 30919AB193, memory clear, ATF drain/refill with pan and magnet cleaning, then Dynamic Check Mode on a workshop lift—not an owner road-test cycle. If the symptom persists after that procedure, it specifies valve-body replacement. Its warranty labor allowance is 1.2 hours for the combined reprogramming and ATF flush; it is not a current retail quote or extended warranty. An older, higher-mileage vehicle needs diagnosis before applying this low-mileage remedy.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Sources for this issue (2)
P0766 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0766 mean on a Subaru?
P0766 stands for "Shift Solenoid D Performance/Stuck Off." This code means the Transmission/Powertrain Control Module detected that Shift Solenoid 'D' is performing poorly or appears stuck in the off position. Shift solenoids direct hydraulic fluid inside the transmission to engage the proper gears or apply the torque converter clutch, and the module monitors whether commanded shifts actually occur. P0766 sets when solenoid D isn't producing the expected result — the gear change tied to it doesn't happen correctly. This can cause harsh or missed shifts, slipping, or being stuck in a gear, sometimes triggering limp mode. On Subaru it is documented across 1 model: Tribeca.
What are the most common causes of P0766?
The most common causes of P0766 are: Stuck or failed shift solenoid D, Low or contaminated transmission fluid, Clogged solenoid screen or valve body passage, Open, shorted, or corroded solenoid wiring/connector, Valve body wear or sticking spool valve, Internal hydraulic leak affecting the solenoid circuit, Faulty TCM/PCM solenoid driver. The specific cause varies by vehicle.
How much does it cost to fix P0766 on a Subaru?
Published repair estimates on Subaru range from $150 to $1,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0766 on a different make?
View P0766 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.