Powertrain, generic · Transmission

P0723 Output Shaft Speed Sensor Circuit Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The output shaft speed sensor (Hall or inductive) reports the speed of the transmission output; it gives the gear ratio together with input speed and on many vehicles also the road speed for speedometer and cruise control. P0723 means the output speed drops or jumps briefly. GM's 2006 tables flag road speed falling below 61 rpm while driving; the 2019–2025 modules count sudden drops (for example 700 rpm) and fail after more than five, after one trip. In Ford vehicles the ZF 6HP26 flags a drop of more than 1000 rpm with the converter clutch locked, the CFT30 more than 6000 rpm per second. The speedometer needle twitches, shifts become erratic and limp mode may follow at times. Loose contacts are the usual cause.

Likely causes

Loose contact, corroded connector or chafing
Electrical interference (shielding, ground, added consumers)
Metal debris on the sensor or loose mounting
Sensor faulty internally (temperature-dependent)

Symptoms

  • Speedometer needle twitches or drops briefly
  • Occasional wrong shifts or downshift jolts
  • Warning lamp
  • Limp mode at times

Repair estimate

DifficultyMediumDIY possible
Parts and labour€80–450
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

output speed sensorsensor wiringtransmission control module

Related codes

P0720P0721P0722P0718

References: gsi.ext.gm.com, newtonnet.co.uk, gsi.ext.gm.com.