Network, generic

U0326 Software Incompatibility With Vehicle Immobilizer Control Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

The vehicle immobilizer control module checks the transponder or smart key and releases the engine controller only after a coded exchange. U0326 means that a controller, usually the engine controller, does not accept the immobilizer's software or stored codes, mostly once either unit has been renewed or reprogrammed. No manufacturer documents U0326 publicly. Subaru uses its own code for this mismatch on 2016-and-later models: B1571, reference code incompatibility between immobilizer and ECM, found by the keyless access module (18-230-26). Chrysler reprogrammed PCMs of 2012–2013 Grand Voyager diesels because handshake failures with the wireless control module were stored as the wrong codes (18-023-13). U0167 is lost contact, U0426 invalid data, U0327 concerns the security module. The engine may crank but not start.

Likely causes

Engine controller or immobilizer unit replaced without pairing the security codes
Used module from another vehicle fitted, carrying foreign codes
Software of engine controller and immobilizer on incompatible levels after an update

Symptoms

  • Engine cranks but does not start, or starts and stalls at once
  • Security or key lamp flashes in the cluster
  • Keys are not recognised after module work

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–700
Time0.5–2 h

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

Parts involved

immobilizer moduleecmcontrol module software

Related codes

U0167U0426U0327U0301

References: static.nhtsa.gov, static.nhtsa.gov, en.wikipedia.org.