Powertrain, generic (extended)

P26DA Engine Coolant Pump Clutch Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P26DA is the high-side counterpart of P26D9: the control line of the coolant pump clutch shows more voltage than the commanded state permits, for instance while the driver should be pulling it low or while it is switched off. Typical causes are a wire rubbing against a live circuit, a missing ground at the clutch so the line floats up, or an open coil that the driver reads as high. None of the carmakers explains P26DA in public sources. CARB requires circuit monitoring for electronic parts that regulate engine coolant temperature, and Ford's OBD summaries confirm that clutched pumps are used on some applications. If the line is held at supply voltage the clutch may be stuck in one state; unlike P26D9 a fuse rarely blows. The MIL comes on and warm-up or cooling behaviour can change.

Likely causes

Control wire shorted to a battery-voltage circuit
Open ground or poor ground contact at the clutch solenoid
Faulty output stage in the engine control module

Symptoms

  • Check engine light on
  • Pump clutch does not switch, warm-up or cooling behaves differently

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–900
Time0.5–3 h

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

Parts involved

coolant pump clutchclutch solenoidwiring harness

Related codes

P26D9P26D6P26D8

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