P2682: Coolant bypass valve control circuit low
Engine coolant bypass valve control circuit low (Subaru thermo control valve)
Severity: Inspect soon
The coolant control valve is not responding properly. Subaru owners report power loss at highway speed along with the check engine and EyeSight lights, so it should be inspected soon.
It gets more serious if:
- Stop: Stop if the temperature gauge rises, a hot-engine warning shows, or the car loses power while driving.
P2682 in short
P2682 means the computer sees a low-voltage fault in the circuit for the engine coolant bypass valve. On 2019 to 2022 Subarus the thermo control valve is the usual cause, and Subaru extended its warranty to 15 years. Owners report power loss with it, so have it checked soon.
This valve controls how coolant flows through the engine and heater. The computer drives it and sets P2682 when it sees the control circuit at an abnormally low voltage.
Generic causes are the valve itself, an open or shorted harness or a poor connection. Loss of cabin heat is a common symptom.
On 2019 to 2022 Subaru Crosstrek, Forester, Legacy and Outback models, many owners report P2682 from a failed thermo control valve. Subaru issued a redesigned valve with a stainless steel shaft and better waterproofing, and extended valve warranty coverage to 15 years or 150,000 miles. Owner complaints say the code, check engine light and EyeSight warnings came together, sometimes with power loss.
Most likely causes
Cause 1: Failed thermo control valve (Subaru 2019 to 2022 models)
Supported by vehicle data- Why it ranks here
- Subaru has a redesigned valve bulletin and a 15-year warranty extension for the thermo control valve, and many owner complaints tie P2682 to it. The bulletin summaries read did not name the code; the owner complaints did.
- What would change this
- Rises on an affected Subaru where the dealer confirms the valve. Falls on other makes.
Cause 2: Open or shorted harness, or a poor connector
Common general cause- Why it ranks here
- The generic reference lists open or shorted harness connections and poor electrical connections.
- What would change this
- Rises if the connector is damaged or corroded. Falls if the circuit tests normal.
Cause 3: Engine computer fault
Possible — needs testing- Why it ranks here
- The reference lists the engine control module among parts involved, but it is a remote cause.
- What would change this
- Rises only after the valve and wiring pass testing.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: On a 2019 to 2022 Subaru, ask a dealer whether the thermo control valve is covered by the 15-year, 150,000-mile extension for your VIN.
IfYour car is covered and the dealer confirms the valve
It meansHave the valve replaced under the extension.
Points to: Failed thermo control valve (Subaru 2019 to 2022 models)
IfYour car is not a covered Subaru model or year
It meansTest the circuit.
Step 2: Have a shop check the valve connector and wiring, and command the valve with a scan tool.
Warning:The valve sits in the hot coolant path. Let a shop do it.
IfThe valve does not respond or its sensor reads low
It meansThe valve needs replacing.
Points to: Failed thermo control valve (Subaru 2019 to 2022 models)
IfThe connector or harness is damaged
It meansRepair the wiring.
IfThe valve and wiring pass
It meansThe computer is a remote possibility.
Symptoms
- Check engine light on, sometimes with EyeSight warnings
- Loss of cabin heat
- Power loss or limp behavior at speed Gets more serious: stop and have it checked.
- Temperature gauge rising Gets more serious: stop and have it checked.
Compare with: Check engine light with loss of power
How to fix
Step 1: With the engine fully cool, check the coolant level in the reservoir.
Warning:Never open the cap on a hot cooling system.
Step 2: Ask a Subaru dealer whether your VIN is covered by the thermo control valve warranty extension.
On your vehicle
SubaruYour car
2019–2021 · Forester
Supported by vehicle dataSubaru 09-119-24 extends thermo control valve coverage to 15 years or 150,000 miles, and several 2019 Forester owners report P2682 with the valve. Whether coverage applies to your VIN is for a dealer to confirm.
2020–2022 · Outback
Supported by vehicle dataSubaru 09-80-21R introduces a redesigned thermo control valve, and 2021 Outback owners report P2682. Whether coverage applies to your VIN is for a dealer to confirm.
09-80-21RStatus unverified
Thermo control valve design change
2020–2021legacy, outback · NHTSA 10253903
A new thermo control valve with a stainless steel shaft and improved waterproofing for the sensor portion.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
09-119-24Status unverified
Thermo control valve warranty extension
2019–2022forester, crosstrek, legacy, outback · NHTSA 10253930
Extends coverage for the thermo control valve to 15 years or 150,000 miles.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Related codes
No curated relationships for P2682 yet.
P2682 questions
Is P2682 covered by warranty on my Subaru?
Subaru extended thermo control valve coverage to 15 years or 150,000 miles on 2019 to 2022 Crosstrek, Forester, Legacy and Outback models. Ask a dealer to check your VIN.
Can I drive with P2682?
Owners report power loss and warning lights with it, so get it checked soon. Stop if the temperature rises or the car loses power.
Sources and review
- NHTSA complaint ODI 11591360
- P2682 OBD-II trouble code: engine coolant bypass valve control circuit low
- NHTSA complaint ODI 11528479
- 09-80-21R: Thermo control valve design change
- Subaru TSB 09-119-24 (thermo control valve warranty extension)
- NHTSA complaint ODI 11515040
- NHTSA complaint ODI 11484851
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
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