P2560 is set when the Powertrain Control Module (PCM) detects that the engine coolant level sensor circuit is reading a voltage or resistance value indicating low coolant level. The code may indicate an actual low coolant condition or a fault in the coolant level sensor circuit itself.
The most common cause is simply low coolant due to a leak (radiator, hose, water pump, head gasket), slow leak, or neglected maintenance/top-off.
The sensor in the coolant reservoir or radiator may be defective, sending incorrect readings to the PCM even when coolant is at proper level.
Wiring to the coolant level sensor may be damaged, corroded, or have poor connections, causing incorrect voltage signals.
The reservoir tank may be cracked, have a faulty vent, or the float mechanism may be stuck or damaged.
An open circuit, short to ground, or other electrical issue in the sensor wiring harness can trigger the code.
The PCM itself may be faulty, but this is the least likely cause and should only be considered after all other possibilities are ruled out.
If the coolant is actually low and the engine overheats, severe engine damage can occur. However, if the code is being triggered by a faulty sensor and coolant level is normal, the engine is not at risk—but the underlying issue should still be diagnosed.
Resetting the code without fixing the root cause will typically result in the code returning, often within the same drive cycle. The underlying issue must be addressed.
No. PCM replacement is almost never the correct fix for P2560. The code almost always points to low coolant, a bad sensor, or wiring issues. PCM replacement is an expensive misdiagnosis that is rarely needed.
A stuck-open thermostat can cause repeated overheating, which may lead to coolant loss and trigger P2560, but the thermostat itself does not set this code—the low coolant level does.