Network, generic

U04B3 Invalid Data Received From Planetary Gear Set Control Module

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

Several hybrid transmissions use planetary gear sets whose shift elements are switched to change the operating mode; two-mode hybrids, for example, combine two extra planetary sets with four clutches to move between electric, power-split and fixed-gear driving. Where a separate module controls such a set and reports its state, U04B3 marks messages from that module that arrive but carry implausible data. No manufacturer documents this code publicly, and SAE gives little more than the name. CARB 1968.2 counts transmission controllers among the emission-critical powertrain units and requires hybrid components to be monitored. U01B2 covers a module that no longer talks. Depending on design, the hybrid system may fall back to a limited mode with a warning light.

Likely causes

Planetary gear set control module or its position sensing faulty

Bus wiring or connector at the transmission damaged or oil-soaked

Software of module and hybrid controller not matching

Symptoms

Hybrid system or transmission warning
Reduced power or electric-only driving unavailable

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€150–2,000

Time1–4 h

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

Parts involved

planetary gear module

Related codes

U01B2

References: law.cornell.edu, en.wikipedia.org.