Network, generic

U0901 Invalid Data from Ion Sense Module

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

An ion sense module evaluates the tiny current that the burning mixture conducts between the plug electrodes after ignition for the engine controller, which uses it to spot misfire, knock and poor combustion; Ford's patent US20170030322A1 places such a module in the ignition system. U0901 means the module's messages still arrive but their content is rejected – a value out of range, an implausible signal or a wrong checksum or counter. No manufacturer documents U0901 publicly. Stellantis' 3.0 L Hurricane six runs a networked ion sense system: its bulletins name U0673 (module silent) and P2F64 (ion sense feedback circuit A), both cured by PCM software. Saab's Trionic T8 module still fed knock and combustion pulses to the controller over separate wires. With bad ion data, misfire and knock detection lose their basis.

Likely causes

Software of the engine controller or ion sense module (update available)
Disturbed data line, for example from ignition interference or a poor ground
Ion sense module internally faulty

Symptoms

  • Check engine light
  • Possibly reduced power from knock protection
  • Misfire or ion sense codes stored alongside

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–600
Time0.2–2 h

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

Parts involved

ion sense module

Related codes

U0673U0353P034CP28C0P0300

References: patents.google.com, static.nhtsa.gov, static.nhtsa.gov, saabwisonline.com.