OBD-II code · Powertrain (generic, extended)
P2556 Engine Coolant Level Sensor/Switch Circuit
General electrical fault on the engine coolant level sensor/switch circuit. Many vehicles use a simple float-switch in the expansion tank, others use a continuous-level analog sensor. With the input invalid the ECM cannot warn for low coolant before overheating starts.
Is it safe to drive with P2556?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen or shorted wiring to the sensor
- PossibleCorroded connector at the expansion tank
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.2–1 h
- Emissions test
- Usually unaffected
- Parts involved
- Coolant Level Sensor, Sensor Wiring
Related codes
- P2553Throttle/Fuel Inhibit A Circuit Range/Performance
- P2554Throttle/Fuel Inhibit A Circuit Low
- P2555Throttle/Fuel Inhibit A Circuit High
- P2557Engine Coolant Level Sensor/Switch Circuit Range/Performance
- P2558Engine Coolant Level Sensor/Switch Circuit Low
- P2559Engine Coolant Level Sensor/Switch Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.