Powertrain, generic (extended)

P26F7 Coolant Pump C Supply Voltage Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Unlike P26F4 to P26F6, which concern the control signal, P26F7 points to the power feed of coolant pump C: the voltage arriving at the pump is missing or implausible. A blown fuse, a relay with burnt contacts, a broken feed wire or a loose ground are the usual causes; a weak battery during cranking can also trigger it. No manufacturer documents P26F7 in public. Ford shows how such a supply fault is detected for its electric engine coolant pump: under P26D3 the PCM concludes that the feed has failed when pump communication is lost and coolant temperature still rises by more than 10 °C. CARB requires electrical faults of monitored components to be found. Without power the pump stops completely, so the loop it serves – heater, low-temperature or component cooling – loses flow until the feed is restored.

Likely causes

Blown fuse or faulty relay in the pump C feed
Broken feed wire or loose, corroded ground
Low system voltage from a weak battery or charging fault

Symptoms

  • Check engine light on
  • Pump C does not run at all
  • Further codes for the same fuse or for low voltage

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–500
Time0.3–2 h

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

Parts involved

coolant pump csupply circuit

Related codes

P26F4P26F8P26D3

References: law.cornell.edu, fordservicecontent.com.