Network, generic

U02C1 Lost Communication With Hybrid/EV Electronics Coolant Pump C

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

U02C1 concerns the third networked pump of the electronics cooling loop, pump C, which has gone quiet on its data line. Vehicles with three such pumps assign them to different branches, and which branch pump C serves is the maker's choice; no manufacturer documents U02C1 publicly. Stellantis' 2024-2025 EV platform shows why the pumps must be kept apart: the units look and fit alike, yet each carries its own part number and software so the EVCU can address it on its own LIN bus, and only the position on the bracket and a symbol tell them apart (STAR S2508000056). Bosch markets electric pumps of this class for cooling power electronics in hybrid and electric cars. Under CARB 1968.2 a mute digital input needs its own fault code. If its branch overheats, power is reduced.

Likely causes

Pump connector or LIN wire faulty
Look-alike pumps swapped between positions during service
Pump electronics or motor failed

Symptoms

  • Warning for the electric drive or charging system
  • Reduced power or charging rate under load or heat
  • Cooling fans running hard

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–900
Time0.5–3 h

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

Parts involved

hv electronics coolant pump cvehicle bus wiring

Related codes

U063DU02BAP0CEAU0648

References: static.nhtsa.gov, bosch-mobility.com, law.cornell.edu.