Network, generic

U0434 Invalid Data Received From Active Roll Control Module

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modePossible

The active roll control module drives actuators that twist the anti-roll bars on both axles against body lean, hydraulically in older designs and electrically in newer ones. U0434 tells that a receiver, for instance the chassis or brake controller, gets this module's status or torque frames but cannot trust their content. No manufacturer documents U0434 publicly. Land Rover shows how faults of such modules surface: notice N733 for the 2022-23 Range Rover and 2023 Range Rover Sport describes front and rear ARCMs that now and then fail to initialise at start, lighting an amber suspension warning, and updates their software. If roll data is invalid, the bars will typically be left passive, so the body leans more in corners and stability functions may be limited. U0133 is lost contact.

Likely causes

Roll control module software fails to initialise reliably

Weak supply to the roll control actuators or module

Internal fault of the roll control module or actuator

Symptoms

Suspension or chassis warning in the cluster
Noticeably more body roll in corners

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€60–1,500

Time0.3–3 h

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

Parts involved

active roll module

Related codes

U0133 U043A U0421

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