OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

P26D7

Engine Coolant Pump Clutch Performance/Stuck Off

The coolant pump clutch is commanded on but does not engage. Coolant flow is missing under load, leading to overheating.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number6 / D7

Possible causes

  • Worn friction surfaces enlarge air gap high
  • Weak solenoid magnetic force medium
  • Carbon or debris buildup preventing free movement low

Symptoms

  • Check engine or transmission warning light on
  • Harsh, delayed, or missing shifts
  • Possible limp mode (locked in one gear)
  • Slipping or shuddering during gear changes

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 200–1200 €
  • Estimated time: 1–3.5 h
  • Component: coolant pump clutch
  • MIL / check engine light

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication