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

P0159

O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)

The ECU detects an abnormally high voltage from the downstream O2 sensor on bank 2. Indicates persistently rich exhaust past the cat, shorted sensor or wiring shorted to voltage.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 59

Possible causes

  • Rich condition on bank 2 high
  • Signal wire shorted to voltage medium
  • Connector pins corroded - high contact resistance low

Symptoms

  • Check engine light on
  • Increased fuel consumption
  • Possible rough idle or hesitation
  • Failed emissions test

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 80–350 €
  • Estimated time: 0.3–1.5 h
  • Component: oxygen sensor b2s2
  • Component: oxygen sensor wiring
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required

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