P26B7: Engine coolant bypass valve C control circuit open

Most likely causes

What to test first

Start at step 1. Each result tells you what it means and where to go next.

1. 1

   Step 1: With the engine fully cold, check the coolant level and look around the bypass valve and its hoses for wet spots, dried coolant crust or a sweet smell.

   Low riskTool: flashlight

   • IfCoolant low or a leak found

     It meansRepair and refill, then clear and retest.

     Points to: Low coolant

   • IfLevel correct

     It meansCheck the connector.

     Go to step 2

2. 2

   Step 2: With the ignition off and the engine cold, find valve C in the service information and inspect its connector and harness for corrosion, coolant, chafing or loose pins.

   Low riskTool: flashlight, service information

   • IfDamaged or corroded connector or wire

     It meansRepair it, clear the code and retest.

     Points to: Damaged wiring or connector at the valve

   • IfLooks good

     It meansCheck bulletins and test the valve.

     Go to step 3

3. 3

   Step 3: Have a shop check for Ford bulletins, command the valve with a scan tool and test its circuit against the service information.

   Best left to a shopTool: scan tool with active tests, multimeter, service information

   Warning:Tests may need the engine warm and running, near hot coolant and moving parts. Leave this to a shop.

   • IfValve does not respond with good wiring, or a bulletin applies

     It meansReplace the valve and update the PCM as the bulletin directs.

     Points to: Failed coolant bypass valve (solenoid C)

   • IfValve and wiring good

     It meansSuspect the engine computer.

     Points to: Engine computer (rare) or software

Symptoms

• Check engine light
• Burning coolant smell
• Limp mode or reduced power Gets more serious: stop and have it checked.
• Temperature gauge rising or overheating warning Gets more serious: stop and have it checked.

How to fix

1. 1

   Step 1: Write down every stored code and the freeze-frame data before clearing anything.

2. 2

   Step 2: With the engine fully cold, check the coolant level in the reservoir and top up with the coolant type the owner's manual specifies if it is low; a level that keeps dropping means a leak to find.

   Warning:Never open the radiator cap or pressurised reservoir while the engine is hot.

3. 3

   Step 3: Ask a dealer whether a bulletin or support program covers your vehicle before paying for a valve; several makers have them for this code.

On your vehicle

Related codes

• P2681Engine coolant bypass valve A control circuit open or out of range

  Same system Common general cause

  P2681 is the same circuit fault on bypass valve A.

• P26A3Engine coolant bypass valve A range or performance problem

  Same system Common general cause

  P26A3 is a performance fault on bypass valve A, where the valve does not do what it is told.

• P1299Ford and Lincoln: cylinder head over-temperature protection is active (the engine computer's fail-safe cooling mode)

  Raises severity Possible — needs testing

  If the engine overheats, Ford's fail-safe cooling can set P1299 and limit power. Treat that as a stop-driving warning.

All Engine cooling (thermostat) codes