Hello! I have a LR2 2008 that is over heating only when I idle with the AC on at a light. sitting in a fast food drive thru, stuck in traffic, at a long stop light.
What I do know:
1. The cooling fan kicks in some times but, not all the time even when it starts to over heat.
2. It does fine and the AC works great on the highway.
3. I have checked all the fuses and they appear good.

Findings so far is that it is pointing to one of four things: Bad Fan - Confused about this as fan is working some times when the vehicle starts to overheat, but not all the time.

With the engine hot and idling (but not yet overheating) pop the hood open and see if the fan is turning. If it is not turning at all you know you have a bad fan.

Check the fuse and fan relay to see if they are getting power. If they are, you’ll need to replace the fan.

Bad Thermoswitch

Thermo switches are electric switches that have a bimetallic component that is sensitive to temperature. Material fatigue is one of the main reasons why this switch stops working.

It’s very important when the car is idling. If it doesn’t turn on the fan in time, the car will quickly overheat since there’s no natural airflow.

One of the most obvious symptoms of this problem is that the radiator fan doesn’t start working at all despite the rapidly climbing engine temperature.

Air in the system Common Issue with Land Rover - Doubt This

This is a more rare reason and you should consider it if there were some kind of recent repairs done on the coolant system.

Sometimes there might be a loose clamp, loose screw, perhaps a punctured hose, or else which lets air into the system.

One more common reason is a loose cap on the coolant bottle. This usually happens when the cap is forgotten to be tightened.

When the air gets into the system, it causes the car to overheat when idling because of extra pressure within the system, much like an air bubble.

Stuck Thermostat - Unsure

The cooling system helps keep the engine from getting too hot, but the engine does need to warm up a bit to achieve optimal performance and efficiency. When you first start your car, and the engine is cold, a small component called a thermostat stays closed, so coolant isn't flowing throughout the whole system. Once the engine reaches its ideal temp, the thermostat opens so coolant can flow and the engine stays at that temperature.



The thermostat can become stuck closed, or might only open partially, causing your cooling system to underperform. There might be sufficient cooling taking place when the car is in motion, but, once stopped, the engine could get too hot. You'll want to have a new thermostat installed that opens and closes reliably.

Radiator Fins Bent - Some are bent, but not a high percentage maybe 5% all in various places.

What is causing these over heating issues?
.

 

Have you scanned the car with a computer that knows how to read LR2 modules? Without that you're mostly guessing.

 

I have and the only HVAC code I get is B105A-71. (Heating ventilation and air conditioner control module) Cabin temperature sensor sensor fan = Intermittent not sure if this would even have anything to do with it?

I have a bunch of codes it is tripping that I think have nothing to do with the problem
P0108-00 = PCM ---------> POWER CONTROL MODULE
P0628 = PCM
P0069-00 = PCM
P0087-00 = PCM
P0480-00 = PCM
P061A - 62 = PCM
U2023-00 = TCM ---------> TRANSMISSION CONTROL MODULE
C2002-62 = IPC--------> INSTURMENT CLUSTER CONTROL MODULE
UO208-08 = IPC
C1A59-13 = BCM -------> BODY CONTROL MODULE
C1D18 - 00= BCM
C1D21-05 = BCM
B1025 - 81 = BCM
B10A2 - 00 = BCM
B10F3 - 13 = BCM
B10F4 - 13 = BCM
B1108-77 = BCM
U0423-86 = BCM
B105A - 71 = HVAC ------------> SEE ABOVE
U0163-00 = ICM ------------> INFOTAINMENT CONTROL MODULE
C1B14 - 15 = PDM --------> PASSENGER DOOR MODULE
B1A02 - 13 = AAM -----------> AUDIO AMPLIFIER MODULE
U3003 - 62 = SRM -----------> SATELLITE AUDIO UNIT MODULE

Looks like I have major problems. Do the modules each need replaced? I was told after I bought it was in an accident, but the car was not totaled. Please help!

 

What this means is that you did not erase all the codes (which may also include historical ones that are not relevant to your current problem). Do so, run your car for a day or two and read them again. You should also reset the electrical system by disconnecting the battery leads, touching them together for 10-20 seconds, waiting 10-20 minutes and then connecting them to the battery. Do this AFTER resetting all the codes.

 

I experienced an intermittent failure of the main cooling fan. Loss of AC would be the very first thing you'd notice. If you sit at idle (or stop n go) eventually the engine coolant temp will start to rise... don't wait for the warning, shut the engine off immediately if it the needle moves above it's normal position. If you can keep the car moving, you'll get enough airflow to control the coolant temp. But if that's the issue, get it fixed asap. If you let it get much hotter than the normal range you'll be in for expensive repairs.

If it's the cooling fan, don't fool with aftermarket fan control modules, they suck. Just get an OEM fan assembly, which includes the module. The fan/module will fail eventually on these cars.

What's your mileage? If it's much over 100K you're probably due for a fan anyway.


I've had this code forever: "Cabin temperature sensor sensor fan = Intermittent". My HVAC has always worked fine.

 

Thank You

I just did a hard reset there is no check engine light at this time. I sit it in the drive with the AC on max and I heard the radiator fan, it never began to over heat. Let you know what happens. I am sure it won't be long till the light comes back on.

 

Maybe you chased Murphy... or he got interested in a neighbor. Be positive.

 

I caught it doing exactly what I described I got a scan done before and after. I just went through and compared the two they read the exact same!

 

How old is your battery, when was it last tested and what is the current voltage? And did you CLEAR the old codes or just thought you did because the check engine went out?

 

That PCM Fan 1 is probably the issue. That's either the fan module, fan, or both. Based on my previous experience I'd get a new OEM (or volvo) fan. It comes with the control module. Especially if you're over 100K.

The HVAC cabin temp sensor fan is probably not a big deal, I've had that for a while and it works fine.

The HVAC CAN bus thing is network comms. You can see that in other modules too. As long as everything works I wouldn't worry about that personally.