02 TD5 90 - EML On & No Throttle + Zero Fault Codes

Im out in Salisbury today for some laning, whole day everything has been spot on. Went through some deep-ish water (rock slider depth), with a good bow wave and wading blanket fitted. Got through fine, no issues carried on for 30 miles or so when I hit a round a about the EML came on and zero throttle response, no other lights.

Plugged in a Nanocom Evo 2, no fault codes read, cleared anyway. Restarted the engine and I could drive, stuttered in 2nd but otherwise fine.

Stopped for lunch, started up after 30 mins sitting. Same thing, EML, no throttle, no fault codes logged.

Any ideas? Sucks as I didnt get to use my new lights and will most likely miss tomorrow laning.

have you looked under drivers seat

Now it could be anything or even just water in the loom ! but if it occurs when starting its possible the starter-motor is causing electrical interference with the throttle circuit for the ECU so the ECU is shutting down the circuit to protect its self.
easy check is clear the fault & bump start, if all ok most likely a lazy starter causing too much electrical noise.
This can be checked properly using an oscilloscope ! to confirm.

Starters fine, starts as it usually does. Alternators fine.

Heading out now to check under the seat.

Have a look at live data for the throttle potentameter

Pcm or ecm what ever you want to call it
Its dead

I was messing around on the nanocom, also unplugged the throttle pot. Then suddenly life, everything worked for 2 mins then EML again

Sounds just like what I had in 2012 shortly after I bought the Land Rover. Mine turned out to be a wiring loom fault. Yes, frustratingly, the engine is in a permanent limp mode and there aren't any fault codes. There are occasional moments when it is OK, but it goes back to limp mode pretty quickly. In my case the fault was between the accelerator potentiometer and the ECU. Because it was intermittent it was hard to pin down so I ended up paying loads of money to a garage, but that's what it was in the end.

Somewhere on the internet I remember reading about people bridging from the potentiometer to the ECU with multi core trailer cable as a semi permanent solution to this problem.

Christ. Potentially, Nanocom was reading the throttle pot fine, all looked normal. Ill try and get some readings later/morninf and post up. Last thing I want is it to happen again in the middle of a lane!

When it first happened to me I was on an unsurfaced road in mid Wales. I drove about five miles to a friend's house on tickover with my yellow light on at walking speed. The anti-stall still works so you can actually get around, even up quite steep hills, just very slowly.

Woke up this morning. Landy was fine, perfect even, until about 1pm when it died again after being turned off for 30 mins.

Still no codes, throttle has voltage and according to the nanocom all is as it should be. Not checked the ECU box yet as I have to take the seat out.

Tested the injectors to check if it was rhe harness, all appear fine.

My money's still on a wiring loom fault, like mine was. I didn't have the Nanocom in those days but the garage told me the faults that were logged. There were a few but none of them related to the problem.

Thats my guess as well. I reckon theres a break in the loom somewhere. Any idea how hard/expensive it is to replace?

I was using a garage some distance from my home, so I didn't keep an eye on what they were doing. They repaired the loom so I assume it was a matter of soldering new bits of wire in. Land Rover in the mid 2000s seem to have got a batch of wire with tender insulation and brittle conductors. I know I'm not the only one to have had loom problems. As well as repair, you can still get new ones I see:
http://www.island-4x4.co.uk/engine-electrics-c-1_2_2399_2530.html
Before shelling out £300 odd, do check I'm right! But the symptoms sound very similar to mine. Long periods in limp mode with a yellow warning light interspersed by a few minutes of normal throttle response.

Sorry to hear you're having so much expense with the Land Rover lately. How's that new clutch and gearbox?

Cheers mate very hepful! I know driving me mad! Lovely! So much better, smoother, quieter, high ratio 5th is great. Cruises at 70 as if it was 60

Finally got home last night about 830. A very long day indeed.

Rolled off the truck and everything appeared to be fine again, still no fault codes showing. Did some research this morning and the more I read the more likely it is to be a chaffed wire somewhere. It's currently in a warm garage which should dry it out...

Tonight's plan will be to remove the drivers side seat and check the ECU for any water ingress, oil in the red plug and checking the green and white wires on the black plug which apparently have something to do with it all. Also going to clean the MAF & MAP sensors, injector harness for oil ingress, flywheel position sensor and the main loom.

Checking yesterday with the Nanocom and a chap who knows TD5s rather well the throttle pot is fine, getting voltage and the voltage changes accordingly when depressed. So I can rule that out.

Problem is, it is intermittent so unless I find a chaffed cable I can't be certain its fixed, which makes me nervous even attempting to drive to the shops!

Well, I wouldn't drive it in that state - it's apt to lose power suddenly without the brake lights going on so someone will run into the back of you! Just a little bump at town driving speeds, but coming out of a motorway slip road it could be catastrophic.

Exactly my fear. Since owning my landy I have become pretty fast at hitting the hazard button! lol

I suppose my point was, I could find a chafed wire, fix it, think its done then it happens again because something else is amiss.

So update.

ECU -
No oil or water in either plug
Signs of water/mud ingress into the seat box

Injector Harness loom - Some oil cleaned and refitted.

MAF - Working fine according to Nanocom

MAP - Cleaned anyway

Currently trying to find the crank position sensor and where the throttle pedal wires go. Im at a loss at the minute...

It's hidden away from prying eyes underneath the air intake pipe on the top driver's side of the bellhousing. Just above the starter motor. The crank position sensor, that is.