U062FLost Communication With Coolant Pump C
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- GM assigns coolant pump C to the pump of its low-temperature coolant loop, a separate circuit that runs well below engine temperature. The 2020 table 20OBDG04 fails U062F once LIN communication errors reach three counts, provided the bus itself is not already faulted (U1345), the pump is configured as present and run/crank voltage is at least 11 V. In 2025 (25OBDG04A) the test watches the pump's response frame CWP_Rsp and fails after 2.5 s without it. Both versions are Type B, so the MIL comes on after two trips. If the pump stays silent, the loop loses its circulation and the parts it cools can run hotter. Electric pumps like Bosch's PDE receive their speed command over LIN or PWM and report their own diagnosis.
- What you may notice
- Check engine light after two trips
- Parts on the low-temperature loop may run hotter than normal
- Likely causes
- LikelyLIN wire, supply or ground to the low-temperature loop pump damaged
- PossibleCorroded or loose pump connector
- PossiblePump electronics failed
- RareLIN master in the engine controller faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.