Coolant Level Sensors
Coolant Level Sensors are designed to monitor the amount of coolant within a vehicle’s cooling system. They provide critical feedback to the vehicle’s control module or dashboard warning systems when coolant levels drop below a safe threshold. These sensors help prevent engine damage caused by overheating due to low coolant levels. In many applications, they also contribute to emissions control by ensuring the engine runs within its optimal temperature range, allowing the ECU to maintain proper combustion timing and fuel mixture.
Common causes of Coolant Level Sensor failure include:
• Electrical connector corrosion or water intrusion
• Sensor float becoming stuck or inoperative
• Coolant contamination or sludge buildup
• Physical damage from improper service or coolant leaks
Symptoms of a failing Coolant Level Sensor may include:
• Low coolant warning light remains on despite proper coolant level
• Intermittent warning light behavior
• Engine overheating if low coolant level goes undetected
• Erratic temperature readings or gauge behavior
• Check Engine Light may appear in some vehicles
The following OBD II error codes are the most commonly found with this product type. In an effort to reduce vehicle emissions, the Environmental Protection Agency (EPA) mandated that all vehicles manufactured after 1996 be equipped with OBD II (On-Board Diagnostics 2) technology. OBD II is now the standard in diagnosing vehicle emissions and system faults, and is implemented across all automotive manufacturers. The codes listed for this product type are common instances that may relate to your vehicle and should be used as a guide only. Walker Products will not be held responsible for any use of this information. It is highly suggested that you consult with a professionally trained mechanic prior to any automotive repair, and that you follow all vehicle manufacturer and EPA guidelines for removal, replacement, diagnostics, OBD II code clearing, ECU, and PCM relearn procedures.
o P2556 Engine Coolant Level Sensor/Switch Circuit
o P2557 Engine Coolant Level Sensor/Switch Circuit Low
o P2558 Engine Coolant Level Sensor/Switch Circuit High
o P2559 Engine Coolant Level Sensor/Switch Circuit Intermittent/Erratic
o U1206 Lost Communication with Coolant Level Sensor Module