Network, generic

U0426 Invalid Data Received From Vehicle Immobilizer Control Module

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modeNo

The vehicle immobilizer control module reads the transponder in the key and passes a coded release to the engine controller. U0426 is logged when that release or status message arrives but cannot be accepted, so the handshake fails even though the module is still talking. Stellantis documents a case on the 2015-2018 Ram ProMaster: the BCM holds U0426-31, labelled Minikrypt error, together with an intermittent no-start and a stuck key; the PCM did not power down at key off, and aftermarket equipment had disturbed the ignition feed circuits, so the voltages at each switch position must be checked (STAR case S2008000160). Ford's 2014 code list includes U0426 without a MIL flag. Lost contact is U0167, a software mismatch U0326; U0427 covers the security module. Typically the starter turns but the engine never fires.

Likely causes

Ignition feed voltages do not match the key position, often due to aftermarket equipment

Damaged key transponder or key not matched to the vehicle

Immobilizer module or antenna faulty

Symptoms

Engine cranks but does not start, or no start at times
Security or key warning lamp flashing
Key hard to remove from the ignition

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€60–700

Time0.5–3 h

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

Parts involved

immobilizer modulecan bus wiring

Related codes

U0167 U0326 U0427

References: static.nhtsa.gov, performanceparts.ford.com, en.wikipedia.org.