P2557Engine Coolant Level Sensor/Switch Circuit Range/Performance
- Generic OBD-II code · Powertrain
- How the car detects it
- P2557 means the coolant level signal is electrically present but not believable. The Deutz EMR L1 engine control is the one documented user and fills the code twice under SPN 111: P2557-00 for a sensor value outside the valid range, and P2557-1C when the supply voltage feeding the level sensor is itself out of range. The second case is worth checking first, because a weak or overloaded sensor supply skews the reading without any fault at the sensor. Mechanical effects can also confuse a level sensor; Mercedes describes for the EQB how an air cushion in the expansion tank pushed the measured level below the warning mark although enough coolant was present. Shorts to ground or open lines belong to P2558, a short to battery to P2559, and P2556 is the general circuit code. Expect a coolant warning that is unreliable.
- What you may notice
- Coolant level warning appears and disappears
- Engine protection warning on industrial engines
- Likely causes
- LikelySensor supply voltage out of range (Deutz P2557-1C)
- PossibleLevel sensor element contaminated or failing
- RareAir pocket or foam in the expansion tank distorting the reading
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.