P26C6: Exhaust Flow Control Valve A Control Circuit Low — what it means, the affected system and what to check before replacing parts.
Meaning, symptoms, causes and checks
The control circuit of exhaust-flow valve A reports a low electrical signal. It does not directly establish insufficient exhaust flow. Ford documents P26C6 for certain Mustang active-exhaust configurations but those instructions are vehicle-specific.
Affected system: Powertrain
Symptoms
- Eligible Ford Mustang models may show an exhaust-mode unavailable warning or engine fault lamp.
- The low electrical signal does not directly measure exhaust gas flow.
Possible causes
- Ford bulletin 25-2146 identifies exhaust seating and tailpipe actuator wiring as vehicle-specific areas to inspect.
- A low control-circuit signal must be distinguished from physical actuator position through circuit tests.
What to check
- Read all related DTCs and the freeze-frame; determine vehicle eligibility.
- Use the manufacturer diagram to assess control-circuit supply and ground; do not infer low coolant or exhaust flow.
- On eligible Mustangs, inspect exhaust alignment and actuator connections per TSB 25-2146.
Also written as: P26C6-00, P26C600 (some scan tools add the fault-type byte, e.g. -00).