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U0672 code meaning

Lost Communication With Engine Coolant Pump

Network system Generic code U06xx codes Check engine light

What U0672 means

GM's 2.0 L LSY and 2.7 L L3B four-cylinders circulate coolant with an electric main pump that the engine controller commands over LIN. U0672 sets when the pump's response frame MWP_Rsp is missing for at least 250 ms (25OBDG03B; same logic in 19OBDG03D for the L3B) once the LIN channel is up, the relay is powered and battery voltage exceeds 11 V; as a Type A fault it turns the MIL on at once. GM bulletin PIP5863C covers 2019-2024 Silverado/Sierra 1500, Colorado/Canyon, Blazer, Acadia, Envision and Cadillac CT4 to XT6: check terminals and crimps, unplug and reconnect the pump, clear the code; if it stays away, release the car. U019F names a separate pump control module, U04A0 its invalid data. Watch engine temperature.

U0672 at a glance

  • Check engine lightYes, usually on
  • Emissions testCan fail
  • Limp modePossible
  • Repair difficultyMedium
  • Typical labor0.3 to 3 hours
  • Clears after repairWhen cleared with a scanner

Symptoms of U0672

  • Check engine light immediately
  • Rising coolant temperature or overheating warning
  • Weak cabin heating
  • Reduced engine power to protect the engine

Common causes of U0672

  • Most likelyPoor terminal tension, crimp or lock at the electric pump connector
  • PossibleLIN, supply or ground wire to the pump chafed or contaminated
  • PossiblePump electronics or motor failed
  • Less likelyPump relay or fuse supplying the pump faulty

Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.

Parts involved

Engine coolant pumpVehicle bus wiring

What each part of U0672 means

UNetwork system: communication between the control modules (CAN bus).
0Generic code: it means the same on every make (SAE standard).
72The exact fault in that area.

What to do next

  • Note U0672 and any other codes stored with it: several codes together often point to one cause.
  • Check for loose connectors and damaged wiring around the parts the code names.
  • Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
  • Clear the code only after the repair. If it comes back, the fault is still there.

Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.

Questions about U0672

What does U0672 mean?

U0672 means "Lost Communication With Engine Coolant Pump". GM's 2.0 L LSY and 2.7 L L3B four-cylinders circulate coolant with an electric main pump that the engine controller commands over LIN. It is a generic code, so it means the same on every make.

Is it safe to drive with U0672?

Drive gently and only to a workshop. With U0672 the car can go into limp mode (reduced power) to protect itself.

Will U0672 fail an emissions test?

Yes, it can. U0672 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.

How hard is U0672 to fix?

Difficulty: medium. A typical repair takes 0.3 to 3 hours of work. This is a job for a workshop.

Will U0672 clear itself after the repair?

Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.

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Technical content: OBDex open OBD-II database (public domain, CC0), checked 5 Nov 2026, edited for US drivers by the VinGear team.
Technical sources for U0672