Powertrain, generic (extended)

P26D0 Engine Coolant Pump Control Module System Voltage Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P26D0 means the electronics in the engine coolant pump see less voltage than they should. On Ford's 2.0 L hybrids (C-Max, Fusion, MKZ) the pump module reports its electronics voltage over LIN, the PCM compares it with the battery voltage it measures itself and sets the code when the gap reaches about four volts for five seconds. Ford special service message 46857 links P26D0 on 2017 C-Max built June to September 2017 to water in a jumper connector shared with the active grille shutter, together with P26CA and U019F; message 47790 extends the corrosion pattern to Fusion and MKZ up to 2019. A voltage drop usually sits in the feed or ground to the pump rather than in the battery as a whole. The pump may slow down, so coolant temperature should be watched.

Likely causes

Water or corrosion in a connector of the pump supply
High resistance in the pump ground or feed wire
Weak 12 V battery or low charging voltage

Symptoms

  • Check engine lamp on
  • Network codes such as U019F stored alongside
  • Rising engine temperature under load

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€30–1,000
Time0.5–3 h

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

Parts involved

smart coolant pump modulecharging systembattery

Related codes

P26CFP26D1P26CAU019FP0562

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