P2558Engine Coolant Level Sensor/Switch Circuit Low
- Generic OBD-II code · Powertrain
- How the car detects it
- P2558 reports that the coolant level sensor or switch signal sits too low on the electrical scale. Deutz assigns it on the EMR L1 controller as P2558-14 under SPN 111 and groups two causes together: a grounded line or an interrupted one, which on that input both pull the reading to the bottom. The repair therefore starts by measuring the signal line to ground and checking it for continuity between control unit and tank, including the connector at the expansion tank, which sits in a hot and wet area. Note that a low signal is an electrical finding, not proof that coolant is missing; an actual low level is logged as P2560. On Mercedes passenger cars, by contrast, the level warning is coded P2556-7B. P2559 covers the opposite short to battery, P2557 an implausible value. The coolant level warning can no longer be trusted.
- What you may notice
- Permanent low coolant warning despite a full tank
- No warning possible if the level really drops
- Likely causes
- LikelySignal line shorted to ground
- LikelyBroken wire or corroded connector at the expansion tank
- RareLevel sensor internally shorted
- Repair
- Easy · Often possible to do yourself.Typical cost: €20 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.