Fault Family System: Network (U-Codes) 21 SAE Codes

Lost Comm Restraints Module

Diagnostic & Technical Explanation

U0151 means a module lost contact with the restraints control module, an impact sensor, seat belt pretensioner, or a similar SRS-network node. This bus is treated as its own protected safety segment because a wiring fault here can mask a genuine airbag readiness problem, so diagnosis must include a full occupant-restraint system self-test rather than assuming a simple wiring repair clears the underlying safety concern. Before disconnecting any restraints connector, the battery must be disconnected and left to sit through the manufacturer's capacitor-discharge wait time, since backup power can fire a pretensioner or airbag during service.

These 21 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 21 times.

Codes in this family (21)

Code	Definition	Repair coverage
U0151	Lost Communication With Restraints Control Module	3 ranked fixes
U0152	Lost Communication With Side Restraints Control Module - Left	3 ranked fixes
U0153	Lost Communication With Side Restraints Control Module - Right	3 ranked fixes
U0154	Lost Communication With Restraints Occupant Classification System Module	3 ranked fixes
U0170	Lost Communication With Restraints System Sensor A	3 ranked fixes
U0171	Lost Communication With Restraints System Sensor B	3 ranked fixes
U0172	Lost Communication With Restraints System Sensor C	3 ranked fixes
U0173	Lost Communication With Restraints System Sensor D	3 ranked fixes
U0174	Lost Communication With Restraints System Sensor E	3 ranked fixes
U0175	Lost Communication With Restraints System Sensor F	3 ranked fixes
U0176	Lost Communication With Restraints System Sensor G	3 ranked fixes
U0177	Lost Communication With Restraints System Sensor H	3 ranked fixes
U0178	Lost Communication With Restraints System Sensor I	3 ranked fixes
U0179	Lost Communication With Restraints System Sensor J	3 ranked fixes
U017A	Lost Communication With Restraints System Sensor K	3 ranked fixes
U017B	Lost Communication With Restraints System Sensor L	3 ranked fixes
U017C	Lost Communication With Restraints System Sensor M	3 ranked fixes
U017D	Lost Communication With Restraints System Sensor N	3 ranked fixes
U017E	Lost Communication With Seat Belt Pretensioner Module A	3 ranked fixes
U017F	Lost Communication With Seat Belt Pretensioner Module B	3 ranked fixes
U0250	Lost Communication With Impact Classification System Module	3 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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