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

P0898

Transmission Control System MIL Request Circuit Low

Voltage on the transmission control system MIL request circuit is below the expected window. Wire shorted to ground or driver low.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number8 / 98

Possible causes

  • Wire shorted to ground high
  • Driver fault low medium
  • Connector pins corroded - high contact resistance 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: 80–400 €
  • Estimated time: 0.5–2 h
  • Component: mil request circuit
  • Component: tcm
  • 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