Network, generic

U0405 Invalid Data Received From Cruise Control Module

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Today the module behind this code is usually the distance radar of adaptive cruise, the unit that asks the engine controller for speed and torque changes. U0405 is set when those requests arrive but fail the receiver's integrity checks. Saab's 2011 code list breaks it down into sub-codes 71 (invalid data), 72 (message counter) and 74 (checksum). Stellantis documents it on the 3.0 L Hurricane six: 2025 Ram 1500 (TSB 18-071-24) and 2023 Wagoneer/Grand Wagoneer (18-076-25) store U0405 together with U0104 as permanent codes with MIL, and the bulletins call the detection false; new PCM software lets the codes clear on their own, which matters where emissions inspections read the MIL. Expect adaptive cruise to drop out while driving is otherwise normal. U0104 is lost contact, U0305 a software conflict.

Likely causes

Engine controller software detecting the fault falsely (update available)
Radar or cruise module sending implausible requests, for example after misalignment or damage
Disturbed CAN traffic from connectors or wiring

Symptoms

  • Adaptive cruise control unavailable
  • Check engine light that does not go out after clearing

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,500
Time0.3–2 h

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

Parts involved

cruise control modulecan bus wiring

Related codes

U0104U0305U0401

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