E12 displayed; engine shuts down and controller indicates low coolant level or coolant loss.

Safety: Allow engine to cool fully before opening the cooling system. Pressurized hot coolant can cause burns.

• Visual inspection: Check under and around the JCB generator for signs of coolant puddles or dried residue. Inspect all hoses, clamps, and the radiator core.
• Top up coolant: Fill the expansion tank and radiator (if accessible) with the correct coolant mixture. Bleed air if the system has bleed points.
• Check level sensor: Locate the coolant level probe in the header tank or radiator. Inspect wiring and connector. Clean the probe if fouled and test continuity or resistance per manual.
• Pressure test: If coolant loss is frequent, perform a cooling system pressure test to locate leaks. Look for white smoke from exhaust or milky oil, which may indicate head gasket issues.
• Replace faulty components: Replace leaking hoses, clamps, radiator, or level sensor as needed.