U019FLost Communication With Engine Coolant Pump Control Module
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- U019F means the electric engine coolant pump, which carries its own control electronics, has stopped answering. Mercedes documents it on two engines: on the M256 six-cylinder the engine controller stores U019F00 or U019F87 with a red coolant warning; LI20.10-P-075374 checks the 12 V and 48 V plugs of pump M75/11, its ground and fuse F153/2 and, if the pump touches the heat shield, insulates it or replaces the controller. On C350e and GLC350e hybrids the check engine lamp lights as well; MED40 software or a new pump fixes it. Ford SSM 46857 and 47790 (C-MAX, Fusion, MKZ hybrids) report it with an MIL from water in connectors such as C1651. Mazda warns that swapped pumps on the CX-90/CX-70 PHEV set it. U04A0 is invalid data.
- What you may notice
- Red coolant temperature warning
- MIL or check engine lamp on
- Engine power reduced to protect against overheating
- Likely causes
- LikelyPump supply plug, 48 V connector or ground loose or dirty (Mercedes)
- PossibleWater or corrosion in front-end connectors (Ford hybrids)
- PossibleSimilar-looking pumps swapped or wrong part ordered (Mazda PHEV)
- RareEngine controller software outdated (Mercedes MED40)
- RareElectric coolant pump electronics 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: €0 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.