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

P0720

Output Speed Sensor Circuit Malfunction

The transmission output speed sensor signal is missing or implausible. The TCM uses this signal together with input speed to determine actual gear ratio; many vehicles also use it as a backup vehicle speed signal for the cluster and ECU.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number7 / 20

Possible causes

  • Output speed sensor failed high
  • Wiring or connector fault medium

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: hard
  • DIY: shop recommended
  • Estimated cost: 200–900 €
  • Estimated time: 1.5–6 h
  • Component: transmission output speed sensor
  • Component: transmission output speed sensor wiring
  • MIL / check engine light
  • limp mode possible

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