Powertrain, generic (extended)

P26C6 Exhaust Flow Control Valve A Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P26C6 reports that the drive circuit of exhaust valve A sits at too low a voltage – typically because the wiring or the actuator has shorted to ground. Ford's 2024 OBD summary shows that the PCM handles it as failure type 11 of the valve A circuit check, which runs continuously and needs about five seconds; the gasoline summaries 2020–2024 carry a typo here and print P25C6 instead of P26C6 in the threshold table. Deutz lists the same code for its MD1 engines as a low voltage or short on the exhaust flap. Ford bulletin 22-2153 for the Mustang names P26C6 alongside other flap codes and a lit MIL, caused by an exhaust that was not seated correctly. With the circuit pulled low the flap can no longer be commanded; the sister codes P26C5 (open) and P26C7 (high) separate the other fault patterns.

Likely causes

Control wire chafed through against the body or exhaust and shorted to ground
Internal short in the flap actuator
Water or road salt in the actuator connector

Symptoms

  • Check engine lamp on
  • Exhaust mode cannot be changed
  • Flap stuck in one position, exhaust permanently quiet or loud

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,200
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

exhaust flow valve aactuatorwiring harness

Related codes

P26C5P26C7P2BF9P26FE

References: fordservicecontent.com, fordservicecontent.com, static.nhtsa.gov, serdia.deutz.com.