P2681: Engine Coolant Bypass Valve A Control Circuit/Open
What Does P2681 Mean?
P2681 is a diagnostic trouble code indicating: Engine Coolant Bypass Valve A Control Circuit/Open. This code relates to the powertrain system. It has been reported in NHTSA complaints across 3 different vehicle models.
Symptoms of P2681
- ⚠️ Check engine light illuminated
- ⚠️ Engine overheating
Common Causes
- 🔍 Wiring or connector problem
- 🔍 Sensor or control module malfunction
P2681 Reports by Year
Real Owner Reports
From NHTSA complaint database — actual owner descriptions.
"Coolant bypass valve. Code is P2681, part will fail and vehicle will consistently display a Engine Maintenance Required Visit Your Dealer on the MID. Dealerships will try and charge 500+ to repair it when the part is under 100+. Problem started to appear since end of March. It's May 15th as of this "
— Toyota Corolla owner, 03/30/2025
"I keep getting a warning sign on my dashboard stating that "Engine maintenance required. Call your dealership". After scanning for codes, I get the code P2681, or that the Engine coolant bypass valve is faulty. After looking online it appears that this is a common issue with this car model. There is"
— Toyota Corolla owner, 06/01/2024
"Around 40k miles I received an Engine Maintenance Required warning. After some research Engine Maintenance and Engine Service Required are two very different indicators. I received and P2681 code meaning the electrical coolant bypass valve had failed unfortunately one can’t tell if it’s stuck shut o"
— Toyota Corolla owner, 09/06/2023
Source: NHTSA Complaints Database
Most Reported Vehicles for P2681
Based on NHTSA owner complaint data.
| # | Vehicle | Reports |
|---|---|---|
| 1 | TOYOTA COROLLA | |
| 2 | TOYOTA RAV4 | |
| 3 | FORD ESCAPE |
P2681 Reports by Vehicle
Detailed NHTSA complaint analysis for each vehicle model.
Frequently Asked Questions
Can I drive with this code?
Will this code clear itself?
How do I find the exact cause?
Reported Repair Costs for P2681
Based on 4 owner-reported repair costs from NHTSA complaints.
⚠️ These are owner-reported costs, not estimates. Actual costs vary by location, labor rates, and root cause. Source: NHTSA complaints database.
What To Do Next
Possible Fixes
- 🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
- 🔧 Test the relevant sensor(s) with a multimeter before replacing
- 🔧 Inspect wiring harness and connectors for damage, corrosion, or loose connections
- 🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.