Fault Family System: Powertrain (P-Codes) 5 SAE Codes

Engine Coolant Pump Clutch

Diagnostic & Technical Explanation

Code P26D6 (Engine Coolant Pump Clutch Control Circuit/Open) sets when the ECM detects an open circuit, out-of-range voltage, or a stuck-on/stuck-off condition while controlling the electro-viscous or electromagnetic clutch on a belt-driven coolant pump, which decouples the pump at cold start to speed engine warm-up. Causes are a worn clutch coil, silicone fluid leakage from an electro-viscous unit, or damaged control wiring along the front accessory drive.

These 5 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 5 times.

Codes in this family (5)

Code	Definition	Repair coverage
P26D6	Engine Coolant Pump Clutch Control Circuit/Open	3 ranked fixes
P26D7	Engine Coolant Pump Clutch Performance/Stuck Off	3 ranked fixes
P26D8	Engine Coolant Pump Clutch Stuck On	3 ranked fixes
P26D9	Engine Coolant Pump Clutch Control Circuit Low	3 ranked fixes
P26DA	Engine Coolant Pump Clutch Control Circuit High	3 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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