Short story (followed by the long saga below):
2008 (model year 2009) L322 Autobiography 3.6 TDV8 with the ZF 6HP26 gearbox. It has about 120k miles on it.
Will go as fast as you want to go up to 3rd gear, but won’t go above that.
GAP II gave me these codes:
U0401-94 (2E)
U0402-94 (2F)
U0416-94 (2F)
U0403-94 (2F)
U0421-94 (2E)
I spend most of my year in Japan, and this was meant to be my vehicle for when I’m in the UK. I’ll be back in mid-December and was hoping the gearbox specialist garage where I had left it (in August) would have figured it out. But after finally looking at it in late October (!) they’re telling me they think it’s nothing to do with the gearbox, it’s the turbos, and I should sell it as is.

Unfortunately, not being in the UK at the moment, I can't give you any more GAP tool readings until I get back.

Any thoughts would be appreciated. For me, there seem to be so many areas where it could be wrong that I don’t even know where to begin.

That's the short version... if you have the time, some popcorn, and you think it’ll help, here's the long version:

I bought the thing in mid-June this year. I flew into Gatwick, went to Reading to pick it up (private sale), changed the motor oil, new filters, and immediately drove it to Prague. Unfortunately, I didn’t have time to do anything else that I would have liked to have done (like change the gearbox fluid). Drove perfectly the whole way there, and also while I was driving around the city. It was pretty damn hot out, you’ll remember (if you were in the UK/Europe at this time)

After spending a week there, we jumped into the truck at about 4am, hoping to drive to Dunkirk that day and catch the ferry back. Immediately, the dash lit up and it wouldn’t go above 10 miles/hour. I’m assuming that this is what is meant by “limp-mode.” Fortunately, knowing the reliability of these things, I had bought gold-plated insurance. I called a tow truck, who took about an hour to get there. By the time he arrived, and I turned the engine back on to drive it onto his flatbed, no more lights, no more limp mode. Nevertheless, we took the flatbed to the Land Rover dealership where they were just opening.

They assured me they could take a look at the truck in… a week to ten days. At that point, with the car working, I decided to take my chances. Not far outside of Prague, having put it on cruise control at about 70mph, I realised that the engine sounded very loud, and then I saw that I was stuck in 3rd gear. I pulled over at a rest stop and parked in the shade for 20 minutes. Back on the motorway and it shifted fine.

We made it as far as Lille where we got stuck in traffic. Did I mention already it was hot out? But there was no sign that anything was overheating. At this point, it was as if the vehicle wouldn’t go into gear… it sort of crept along, revving high; that rectified itself finally as it seemed to clunk into gear, but the check engine light wouldn’t go out. We managed to get off the motorway and get to a hotel. The next day, no change: check engine light and nothing above 3rd gear, so we called it quits and used the breakdown coverage to get us home; the car followed a month or so later after they couldn’t find anyone who would even look at it.

Back at the house, I finally changed the gearbox fluid, filter, and pan, hoping that would help, but no. It’ll go as fast as you can go in 3rd gear, but it won’t move above 3rd gear. I thought about changing the solenoids, but didn’t have time to order the parts and get it done. Plus I had no indication that that would do anything; maybe it’s the dreaded E clutch. I noticed the battery seemed to be at 12.7 (i seem to remember), so I took it out and charged it fully. Put it back in… no change. The battery, according to the former owner, had been changed in February (and that matches the dates on it).

At the beginning of August, I had to return to Japan for work, so I sent it to a gearbox specialist. After finally looking at it, he decided it wasn’t the gearbox, and he was having someone come to read the codes. That was a little disappointing. This “code reader” decided that the turbos had both gone. But… I was able to drive the thing full tilt at 50mph; the only limiting factor seemed to be the gearbox not going above 3rd.

The plan now is to send it to a Land Rover specialist, who can’t look at it until January. So maybe, just maybe, I’ll get the thing working for next summer when I’m back.

Any thoughts would be appreciated. Here's a photo of the beast in Prague in late June.

The gearbox will go into limp mode if the engine is in limp mode, which is what seems to be happening.
All those DTCs refer to communications (CANBUS) faults between the engine ecu and other ecus, not anything wrong with the engine itself such as failing turbos.

Thanks Graeme; so, just so I understand the meaning of "limp-mode", even in limp-mode, the engine will still go as fast as I can get it to go in 3rd gear? I thought limp-mode would cause the truck to not go past a certain speed.

And just to show my complete idiocy (which I'm going to attribute this to severe jetlag and advancing age), I left out a part about me having replaced the turbo cooler hoses with silicon hoses when I was in Prague, and I forgot to tighten one of the clamps. Just as I was about to cross the border from Germany into NL, one of the hoses popped off (going about 120km/hour), causing a loss of power (obviously) and a cloud of smoke behind us. I pulled off, reattached the hose, and tightened the clamp. Started up again and drove a few more hours before the issue in Lille. But again, I'm not seeing any sign that either of the turbos aren't actually working.

Clive

Engine limp mode limits fuel, whereby the engine will rev whilst there is little load but as soon as significant load is applied that would require significant fuel the revs will be quite low. In 3rd gear once speed increases the engine load is quite light so doesn't consume much fuel to rev. However some restricted performance events don't limit performance to the same extent as some other faults.

The i/c hose coming off hopefully hasn't caused damage as whilst the turbo would spin more freely due to reduced back pressure from the inlet manifold, the cylinders wouldn't be getting the oxygen required to drive the turbo faster. My TD5 D2 had a similar incident but it didn't cause any damage.

It would be prudent to clear the current codes then read the codes again quite soon after another limp-mode incident in case there are faults other than the comms faults.

Thanks again, Graeme - I think I understand the limp-mode description. And yes, I'm pretty sure that the turbos continue to work (despite any damage the hose blowing off may have caused, which isn't yet evident).

I cleared the codes numerous times while I was there last August, but the issue with not advancing past 3rd gear continued nevertheless, and that's where it has stayed. I'm looking forward to seeing if the Land Rover specialist place can give me a better idea of what's going on than the gearbox specialist.

Are the codes still only the ones starting with U? Low voltage at the ECM can cause comms faults which have been found to be caused by a failing battery in other LRs, but possibly also a failing alternator. The alternators used by LR have a habit of short-circuiting their power diodes which are avalanche diodes that reverse conduct when voltage exceeds their trigger voltage which lowers with age thus eventually causing a dead short. Hence intermittent loss of charging capacity soon becomes a battery-destroying event.

You've just reminded me that (thinking the alternator might be shot) I bought a new alternator, radiator, and gearbox oil cooler, with the intention of replacing all of them (I wasn't able to find out if the sludging issue with the gearbox cooler was still applicable in 2008, but thought what the heck).

I started to remove the front end to get the radiator out (to eventually get to the alternator), but finally realized that with the 3.6 I actually can't remove the radiator without emptying the a/c system. So instead, I took the battery out, recharged it fully (above 14, I seem to remember), and put it back in. It didn't make any difference to the 3rd gear issue, but (if the alternator was fried) perhaps the battery was already ruined by that point (despite being 6 months old).

Unfortunately, being in Japan, I can't answer the question about the current codes until I'm back in December. But I'm definitely going to let the Land Rover place know about the potential alternator issue. Thanks again.

Just an update for anyone who is interested.

Back in November, as a reminder, the transmission specialist had said it wasn't the transmission, it was the turbos, and I was looking at £6000 to replace them... so he would find someone to take it off my hands.

I didn't believe that was the issue, so I had it towed to a well respected garage in Carmarthen. They couldn't look at it for several months, which was fine... I was in Tokyo until mid-June. At the end of March, he called me to say it was fixed and I owed him £60. According to him, one of the MAF sensors had become unplugged; he plugeed it back in and it was fine. When I had stopped crying from relief, he told me that the vehilce had stopped rolling in traffic in Lille because the belt in the transfer case was jumping off its cogs, and it would do it again more and more frequently; he suggested a reconditioned transfer case. He also said that the rear diff was whining very loudly, and he recommended a recon unit.

I was happy to pay for both of those. I picked the truck up in mid-June, and drove it to Paris (new assignment) a week ago.

I've had a "limited gears available" issue twice now since I picked it up: once within a few miles of leaving the garage, and once on the drive to Paris (around Cardiff). Both times, I pulled off, turned it off for a few minutes, started again, and it went away.

Unless it becomes an ongoing issue, I think I'll try replacing the solenoids next time I do the transmission fluid, and (see another post I just made about the hedgehog) I'm trying to track down an electrical fault.

All in all, at least I'm getting to drive it now, and have at least a tiny bit of confidence that I'll get where I want to go.

Wow, dodged a bullet there....

Glad it's "nearly" sorted.....  Pete

__________________________________________________
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-

“He would find someone to take it off my hands”
My antennae would be twitching then.  John
2008 Stornoway Grey 3.6 Tdv8 Vogue
2005 TD6 Java Black Vogue - Written off!!
GAP iiD BT
2003 Discovery TD5 Auto, Nanocom Evolution - gone to a new home!
MasseyFerguson 152 - No electronics!! - Sold

Exactly.... although the fact that I could go 70mph in 3rd gear sort of gave it away...