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

P26D0

Engine Coolant Pump Control Module System Voltage Low

The smart coolant pump module reports the system voltage below operating range. Pump output is reduced or disabled to protect the module.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number6 / D0

Possible causes

  • Weak battery sags voltage under load high
  • Alternator output below regulation point medium

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 120–800 €
  • Estimated time: 0.8–3 h
  • Component: smart coolant pump module
  • Component: charging system
  • Component: battery
  • 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