2010 LR2 Rad Fan won't stop, even when engine is turned off

Possibly a stuck relay. They can fuse contacts and be stuck in the closed position. Find the fan relay and swap it with another. Preferably something that's using the same relay with a visible function, like maybe fog lights.

I know nothing of the LR2, but that's basic first-level electric diagnostics. Past the relay you're dealing with the engine management computer. If your car runs, the computer works. So that leaves you to next-level diag, which is that computer getting bad information from elsewhere, such as a bad coolant temp sensor. In many vehicles, the system uses that input for multiple purposes, like sending the ECU into closed loop, running a fan and showing temp on a dash gauge. Is that gauge working? that may mean nothing as many manufacturers are using damped gauging- shows mid gauge unless dead cold or boiling hot. But worth a look.

The power to the fan is controlled by the Fan Control Module attached to the fan cowling. I hope the following gives you some insight.

The Engine Control Module (ECM) controls the fan speed via Pulse Width Modulation (PWM) signals to the Electronic Fan Control Module (EFCM)
The fan speed is controlled at 4 levels:
- Run-on occurs in 3 stages (i.e. depressing the fan speed)
- The engine cooling fan is activated a certain time after the engine has been switched off to protect various engine components from overheating
- The time the fan is activated and the speed of the fan is dependent on the coolant temperature and the driver's driving style (engine load) when the engine is switched off
- The hotter the engine and the hotter the load, the higher the fan speed and the longer run-on time. The maximum time of run-on is 360 seconds
The EFCM can, by modulating the PWM control signal, inform the ECM about the fan's status and any faults.
PWM control of the fan motor provides variable control of fan speed to ensure minimum fan noise and reduced energy consumption when fan operation is required. The control module is mounted above the wade water entry lines
For additional information, refer to: Electronic Engine Controls (303-14A Electronic Engine Controls - I6 3.2L Petrol, Description and Operation).
The coolant expansion tank provides an expansion volume and permits easy in-service bleeding of the cooling system. Coolant level sensing is precise to provide early warning in the event of low coolant level. To prevent intrusion into the expansion tank's casing, which could be a potential leak path, a magnetic float within the tank activates a switch located outside the tank.


The temperature of the cooling system is constantly monitored by the ECM via the ECT sensor signal. The ECM uses the ECT signal to control operation of the cooling fans, and to adjust engine fueling. The ECM also operates the fans in response to inputs from the automatic transmission oil temperature sensor, Air Conditioning (A/C) system control switch, and the A/C pressure sensor. For additional information, refer to: Electronic Engine Controls - 2.2L Diesel (303-14 Electronic Engine Controls - 2.2L Diesel, Description and Operation).
For additional information, refer to: Air Conditioning (412-01 Climate Control, Description and Operation).
The cooling fan speed is also influenced by vehicle road speed. The ECM adjusts the speed of the cooling fans to compensate for the ram air effect, using the CAN bus road speed signal received from the Anti-Lock Brake System (ABS) module.
When the engine is shut down, the coolant temperature and volume decrease. The thermostat starts to close as the coolant temperature decreases to 89°C (192°F), and is fully closed at 81°C (178°F). The coolant level within the reservoir decreases as coolant is drawn from the reservoir to replenish the system.
Following engine shut down when the coolant pump is stationary, the ECM may continue to operate the cooling fans for a pre-determined period to maintain engine cooling.