Hello, i have three strange problems that happened simultaneously with a battery replacement.
First thing I noticed was viscous fan roaring all the time. I had fan replaced with a factory unit but made no difference.
Second was Outside Temp sensor which began reading -40c, or sometimes -2c or -3c i had the sensor replaced (in the wing mirror). Made no difference, so forked out and fitted a good used wing mirror. Made no difference.
Third problem - when I started car morning after battery fitted, it started as normal and revved as normal, but as soon as I put it in gear, the revs drop back and the throttle is completely unresponsive for at least 20 secs and then suddenly responds. If I let the engine warm up the problem is nowhere near as bad, but some throttle delay can sometimes be noticed. Only significant fault codes were MAF, now replaced but made no difference, and a throttle position reference (which I forget(. Strangest thing is NO warning kights in dash
Any thoughts, help or advice would be greatly appreciated, many thanks, Geoff

First off, as you have found, don't just change things when a fault code appears, 95% of the time it is not the item that has failed but the fault system itself....

You have classic voltage issues, they like to have a charged battery and get upset with lower voltage...

Disconnect the battery, give it a full overnight charge then reconnect and take it from there....

Also, fill out your vehicle details in your profile so we know which model etc you have...  Pete

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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Thanks Hayland I'll try that (and update my profile ta)

Please stop using your current garage and replacing parts willy nilly - they clearly like to cash in (sorry, but it's true).

As Haylands has suggested, I'd start with the battery. Then I'd move onto the causes, not the symptoms of fault codes. Very rare for a 4.4 TDV8 to develop any of the issues you have described. 2015 Range Rover Autobiography 4.4 SDV8

The car always goes to an independent LR specialist, and they are very good. Problem is they are in such demand that there's a 10 week wait for an appointment. So in the meantime I ordered the fan and wing mirror on Ebay and was convinced that would cure the problem, but it's obviously some other problem, likely electrical.
The battery is new and well charged, and I've tried leaving it disconnected overnight but to no avail. The fact that no throttle response when engine/transmission is cold, but ok when it's warm should point to something but i can't think what.

Sounds like it could be poorly fitted multiplugs after previous repairs?

Unlikely, but also possible to be the PCM. 2015 Range Rover Autobiography 4.4 SDV8

I would check all power and earth connections in the vicinity of the battery.

Thanks, I'll check the multiplugs and connections around the battery area but tbh I'm not hopeful. The lack of throttle response when selecting 'Drive', but only when cold, has me completely baffled. It's a pain waiting five minutes for engine/transmission to warm up before you can go anywhere, especially when you're running late!
When (if!) it eventually gets sorted I'll be sure to post details - it seems so unusual that I'm sure the reasons would be of interest to other owners.

Try doing a Hard reset & see if that brings back the original settings.

Thanks Highlander, tried that but no difference

It would be wise to invest in a GAP IID tool so you can do proper diagnostics. It will pay for itself very quickly and can be sold for a near new price if you move on from JLR ownership. Most here wouldn't contemplate L322 ownership without one... 2012 TDV8 Vogue (L322)

Thanks Jaygee, i've been thinking that. Would a generic one do the job, or would it have to specific to RR? Any recommendations ( at a reasonable price)?

The GAP IID bluetooth is by a large margin the preferred device and will do a lot more than a generic code reader.
https://www.fullfatrr.com/forum/topic65903.html 2012 TDV8 Vogue (L322)

Thank you, appreciated

With regard to Cooling Fans, I found that a lot of Jaguar and Landrover parts interchange, and in the Ford era, Ford parts. Key Modules have Volvo stamps for instance. I had, some years ago a full speed fan on a Jaguar V12, and found, upon dismantling the fan motors and resistor pack that the resistor pack was heavily corroded, and fell apart. So its worth disconnecting the fan multiplug, and check the resistances and whether you are continuously drawing full power. A stuck Air Con relay can do the same, but its also worth doing a diagnostics check just in case, but often faults at the front of any vehicle are corrosion somewhere.