I’m brand new to the Discovery world but not to cars and enjoy working on them. I recently purchased an 03 Discovery to be used as a camping/adventure vehicle for my son and I, with 95k miles, all stock. It has had all of the previous services done confirmed with a car fax report.
I just registered it and now need to get it smog but it is currently throwing a 1481 code. I’ve been trolling around on a few threads regarding this issue but can’t quite drill down where to begin. I don’t mind spending money on parts, just as long as they are the right parts and actually accomplish what I am trying to fix.
I have an ultra gauge and when I perform a system test, my evap system is the only one that is not ready. Also to note, my truck likes to run around 210F while cruising around and at stop lights it heats up to 221F. I will be tearing into it soon and replacing head gaskets, arp studs, new oil pump, water pump, timing gears and chain, plugs, coils, wires, cooling system flush, but that’s a story for another day.
At the moment, I need help sorting out this trouble code. There’s currently no light on....thanks.

 

I think you are on right track with the 1481, leak pump or wiring issue....(maybe vacuum leak?)

as for 210-220...does your front fan come on??(the one in front of radiator...) because if not, add a wiring harness check, low temp thermostat , new hoses and fan and temp sensor to list of needful things....

Build tip:: as far as rebuilding top end on these engines...'easy!'....The hardest part is getting the four coil screws removed....loosen the bottom two, remove the top two, then the lower intake comes right off......you will also need a short flex impact strength socket for head bolts (5/8th, and in a few lengths, all 1/2" drive) and a short flex 12pt 12mm (3/8th drive) for exhaust bolts.....see pic below

and get the correct engine fan removal tools....and open end wrench and a hooked holding tool....well worth it....

 

Thanks for the direction and tips. I’ll check the fan when I get a chance. I think I read that it’s supposed to cycle on at around 210F, right?

I’m excited to dig in and bolster up a few of the prone areas. Having a major issue out on the trail with my 6 year old son is a situation I would like to avoid.

im hoping to start the head gasket process tonight. I will be replacing the t stat with a 180 td5 unit too.

 

@PanicDisco read the thread on the inline mod, in the end it is a better choice it makes thermostat replacement choice a no brainer. There are a lot of dodgy aftermarket Discovery thermostats out there.

Having said that I have run a black TD5 thermostat for the last year while tracking a cooling issue it works well, but I have an inline going in the next couple weeks simple for ease of maintenance and service on the trails.

Also if you have the original thermostat those are normal temps.

Finally on head gaskets, get the heads checked for true. And remember aluminum no metal scrappers for gasket cleaning

 

Thanks again for the advise. I was worried I was getting close to frying my engine with those temps at idle...we’ll tonight begins the rebuild process.

update on the secondary cooling fan, it’s corroded and stuck. Possibly the cause of my p1481 code. Which, now that I think about it, the code pops up on my ultra gauge when the temperature hits 212 F or so...makes sense. I’ll replace and update.
I’m shocked at the cost of this simple little electric fan...any part numbers for motors that’ll fit the space of the frozen motor? It looks like a motor I could find on Amazon...?
Thanks again for the help.

 

do a search for fan motor repair...several have done it. I bought a great used unit off ebay (don't buy one with any rust showing)...runs like a champ..

 

Quick update: head gaskets just replaced. ARP studs installed and torqued to 80 ftlbs. New timing chain and gear set, new water pump, new oil pump and oil pan gasket. New coils, STI 8mm wires and champion 2x platinum plugs, 180 thermostat and as icing on the cake, I replaced the crank position sensor and mass airflow sensor. My truck is running like a top just in time to take my 6 year old son on his first backpacking trip up in the Sierras!
I still need to sort out that random p1481 code. However last night, I replaced a blown 30 A fuse and rebuilt the electric fan motor, so I’m really hoping that did the trick...I’ll find out when I drive it next.
I should pass smog now and can finally completely register this awesome truck in my name. Fingers crossed!

Thanks to those who helped me along the way.

 

Did you ever get the P1481 code resolved? It's one of two codes mine keeps showing me on the ultraguage

 

It turned out to be that darn electric fan. Replaced it and the code never came up again.