Hi all,

I’m truly struggling with the cooling fan at this point. I’ve replaced the entire cooling system, gone through several fan modules (all gates), had the purple power wire replaced, and am now on my third fan assembly (VDO units). I’ve had intermittent success, but eventually run into another failure. Close to giving up quite frankly.

Replacing the fan and module initially worked.. after sometime that failed. Replaced the module again.. worked for a bit then failed. Addressed the power wire… worked for several months then failed again. Replaced another module. Brake vac pump started oil one day and fan stopped working.. rebuilt the pump and replaced the fan module again... worked for a few days then failed a few days later with the fan stuck on draining the battery. Swapped with a new module to test and same issue.. replaced fan assembly and module again.. worked for about a month and now I’m back to my hell with a no fan.

Is the ECM the next culprit? The connector from the ECM wiring to the fan? I don’t have auto logic or any fancy diagnostic tools, but might be forced to go down that route or give up and I don’t like giving up.

@p_gill I know you are out there somewhere

Thanks all in advance https://www.youtube.com/c/HeelTow

Still looking for help here.

Since posting I’ve replaced another fan module and fan both new.. I crimped on a new fan module plug. Without starting the car or even inserting the key fob in the dock fan powered on immediately when plugged in.. at this point removed the cables from the battery and am letting the computer reset while doing a fun recharge/reconditioning cycle of the battery. Barring a short circuit that I have yet to identify or a fail safe mode triggered by the ecu I’m at a loss.

Any two cents here would be appreciated. https://www.youtube.com/c/HeelTow

Sounds pretty frustrating. It sounds like a dead short to me, as I can't think of any reason the fan should power up without the key in the dock. I guess one thing that's in your favour is that you have something positive (power to the fan) as opposed to having something negative (no power) so at least there is a path to follow.

On the i6 I think it's Fuse FE3, 80A in the Battery Junction Box. I'd pull that to stop your battery drain and then go looking for your short. Crushed or pinched harnesses after major work, or chafing in the footwell harnesses are some likely candidates.

Thanks for the reply truly lost. I took off the negative terminal cable and put a test light on the terminal which has been coming back with a signal. A short is what I suspect but I’m still struggling to trace it.

I believe I’ve pulled almost every fuse and relay in the trunk and engine compartment (will get to the passenger compartment soon). The only two I haven’t pulled in the engine bay fuse box are F20 and F21 as there is no space to get an 8mm socket in there. I’m trying to figure out how to move that black plastic FoMoCo bundle up but it may require removing the battery tray.. which I’m not trying to do to keep the test light on. More than likely by the time anyone responds I would have done so anyway so probably a moot question.

F17 and F18 are for the passenger fuse box supply and since I’ve pulled those with no change is it safe to rule out the passenger fuse box altogether? Or am I thinking about that the wrong way? If it isn’t F20 or F21 (luggage compartment fuse supply) then I’m obviously going to run through the entire passenger compartment box. Still curious for my own limited knowledge. Thanks again

So far the only findings were some random broken glass in the trunk/under the rear seat bracket which is puzzling given the suv has always been in the family and there has never been any broken/replaced windows or broken glass in the car for that matter. 😂. https://www.youtube.com/c/HeelTow

well i've checked for a short to ground and short to power on every fuse and relay I could identify. Nothing. Inspected as much wire as I reasonably could. At this point I'm going to give up. Fiddling with the negative terminal anytime I want to drive/park the car is as good as a solution as I've got for now. Perhaps install a switch at some point. Not the right fix, but I'm out of talent and resources.

I have one hail mary left and that is if anyone can point me in the right direction for the diagnostic software the technicians use.. VIDA? or is that only for the Volvo guys. Thanks https://www.youtube.com/c/HeelTow

final bump on diagnostic software - thanks https://www.youtube.com/c/HeelTow

Sorry you're not getting a lot of traction on here. I guess diagnosing electrical wiring problems on the other side of the world is very difficult, and we can only generalize.

If your fan always runs, and that's your only problem, I would focus on tracing that circuit comprehensively. Figure out how it works and how it is switched, and trace the wires. It doesn't sound like a logic problem (i.e. easily diagnosed with software) because the logic isn't even awake without the key in the dock.

In the past I have used a divide and conquer (concur lol) methodology: break it down into halves and test each half. One half will work, the other not. Do it again, and again, until you find the fault. On your side you have two things in your favour: your fault is caused by the presence of power to the fan, so you have a positive thing there; and it's always on, so the fault is consistent. Against you is that neither you nor I fully understand the system, so we don't know how it's meant to work or what it looks like when it's normal.

So I guess try and get your head around how it's meant to work (is the fan switch adding power to the circuit, energizing it; or grounding the circuit, letting the current flow to ground? What possible combination of system wakefulness allows the fan to run - from engine running through to locked and sleeping. What logic makes the fan run? Aircon on, temp sensor reading high etc.) and then mapping it out very clearly so that you can understand and critically, test it.

As said above, it is very hard to diagnose remotely.

Extract from the Repair Manual

Common to both fan types are:
Electric motors with brushes
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

Most systems on the FL2 are monitored to check that they are within normal bounds and give error codes for faulty sensor readings. The Repair Manual has a at least a page of these.

Are you sure that the Fan is not working normally and the fault lies in the fact some sensor, or sensor wiring fault, is telling it to operate.

The fact that you are getting it working normally sometimes may indicate that you are disturbing some damaged wiring or loose connection.

PS I am not sure from reading your initial post that you know that the fan signal is PWM (Pulse Width Modulation) and can be seen with a 'Scope'. FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

2010 HSE auto
Hello all, been reading this with interest, so decided to look at my car and try a few things.
There are two fans behind the radiator.
Switched on engine running and all heat controls switched off, the fans do not move.
switch on aircon, i can hear a fan? running but the fans behind radiator are not moving.
Could some kind person please explain to me what should or should not be happening.
With the controls at zero there is cold air coming through but not freezing.
Moving up to hot and everything seems ok,
Put on defrost and there is definitely a blast coming through.
help please
Thank you Jim A
Fl2 HSE 2010 auto
Disco 2Td5 auto 2002 gone
Disci 1 300Tdi auto 1996 gone

This is what the JLR workshop manual says for the TD4...

Engine Cold
During engine starting the coolant pump is driven by the camshaft drive belt and circulates coolant through the engine
cylinder block, engine oil cooler and cylinder head. Coolant also flows through the climate control heater circuit and the
EGR cooler. The thermostat is in the closed position and prevents the return of coolant from the engine to the radiator.
With the thermostat closed, the by-pass valve is open and directs the return coolant through the thermal control module
and coolant rail to the coolant pump housing. The coolant continues to circulate and is progressively heated by the engine.
Entrained gases in the cooling system escape through the thermal control module degas line to the coolant reservoir.
The increasing coolant temperature is felt at the thermostat, and is registered on the instrument cluster coolant
temperature gage via the ECM and ECT sensor signal.
For additional information, refer to: Instrument Cluster (413-01 Instrument Cluster, Description and Operation).

Engine Normal Operating Temperature
With the coolant temperature increasing, at 83°C (181°F) the thermostat reacts and commences opening. The by-pass
valve is progressively closed. Hot coolant returning from the engine to the thermal control module is now allowed to pass
through the top hose connection to the radiator. The flow of hot coolant to the radiator now forces cold coolant within the
radiator and bottom hose to flow to the thermal control module.
During the thermostat opening period there is an initial temperature differential of the coolant at both sides of the
thermostat. The thermostat reacts to the temperature differential and partially closes, while the by-pass valve opens
further. The thermostat and by-pass valve continue to oscillate while the coolant temperature increases.
At a coolant temperature of 91°C (196°F) the thermostat is fully opened and the by-pass valve is fully closed. The return
coolant from the engine is now fully circulated through the radiator and bottom hose. Coolant flows through the radiator
from the RH tank to the LH tank, and is cooled by air passing through the matrix. Entrained gases in the radiator escape
through the connected degas line to the coolant reservoir.
The increased coolant volume created by heat expansion causes the coolant level to rise through the connecting reservoir
hose, and into the reservoir.
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.


The I6 engine cooling is a bit different in that it can have 1 or 2 radiator fans. Jules

Jules, thank you for the information.
Have read it a few times and beginning to understand how the fans work.
I assumed(never assume) that if i switched the aircon on at the coldest the fans would run when the outside temp was about 18C.
Aircon was refilled last year . Air is cold but not really cold.
Just like to have everything on car working properly
Thank you Jim A
Fl2 HSE 2010 auto
Disco 2Td5 auto 2002 gone
Disci 1 300Tdi auto 1996 gone