Disco 2 TD5 no throttle action, with a three month old NEW pedal!

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yfo866

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OK guys and gals, i need help! Or rather the Disco does, as it's at serious risk of getting a damn good thrashing with a big branch...(i have SEVERAL to choose from as i severely pruned a small tree about a month ago)
Not long after christmas the pedal stopped working. So i looked at the price of a new one. After regaining conch concsh, came around, i opted for a second hand job off ebay.
That one worked for about three weeks until it left me stranded at work with a very pleasant, albeit bloody slow drive home on tickover. It normally takes about 17 minutes. That night it took an hour and a half.
Well since then it's been great!
Just jumped in to go shopping, pulled off the drive and had no go. Switched off and on again, still the same so backed it back and jumped in the Ibiza and did the shopping...
Who thinks there should be a minimum speed in supermarkets?

So, as it's a brand new throttle unit from Craddocks, i'm assuming it isn't the cause, so what else could cause this little negative impact on my joys of motoring?
I won't ask my mate who owned a TD5 Defender, as he seems to blame the crank pully for everything.
 
Check the wiring loom, from the pedal to the ECU. Im told its prone to the insulation of the wiring chaffing on the engine/gearbox. Open up the plastic conduit, and check the wiring closely. There have been cases on here where the individual wire insulation is rubbed away, but the outer conduit appears ok.
 
+1
Have you got the fault codesfrom a decent code reader? The loom is the likely culprit though as above. If you can get a good one from a breakers may be your best bet
 
Check the wiring loom, from the pedal to the ECU. Im told its prone to the insulation of the wiring chaffing on the engine/gearbox. Open up the plastic conduit, and check the wiring closely. There have been cases on here where the individual wire insulation is rubbed away, but the outer conduit appears ok.
Thanks for that, i'll have to have a look.
 
+1
Have you got the fault codesfrom a decent code reader? The loom is the likely culprit though as above. If you can get a good one from a breakers may be your best bet
I bought a Lynx code reader for the Disco 1, but as yet have never used it. I think it works on the Disco 2 as well.
I haven't plugged it in yet as i had to go shopping then to work not long after getting home. I'll have a play over the weekend.
I bloody hate wiring!
 
Right... Here's the latest!
After ten minutes of faffing about registering and updating the Lynx, i got the following faults:


Under Engine - Lucas TD5 EMS
Airflow Circuit Fault - logged

Driver Demand
1 Out Of Range Fault - logged

Driver Demand
2 Out Of Range Fault- -logged

Faults Detected With Driver Demand - logged

Road Speed Missing Fault - logged

Can Error Fault - currently active

Road Speed Missing - logged

Injector 5 Peak Charge Short - logged

After getting rid of the fault codes, the ones above remain and the ones below are gone.

Under ABS

Engine Speed Input Signal Intermittent Or Missing

Under Airbag

Airbag Control Unit Fault Intermattent
Open Circuit Fault In LH Pretensioner

I've just been out looking for the cable that goes over the gearbox. Can't find it. Other than a thin white wire that i think routes around to the other side of the engine, and a thin black wire which is missing a connector that starts at the same place, some metal thing under the exhaust manifold and near the oil filter. Actually the black wire has been cut.
Where does the loom from the pedal go to? Maybe it would be easier to trace it from the other end? Does it exit the bulkhead in that inch and a half thick bundle of wires above the steering column?

Oh, and FYI, the throttle worked after i grilled it with the LYNX. When i popped out to read the fault coded again tonight it still works.
Are there any versions of this engine that had a good old fashioned throttle cable, like the 300TDi engines?
I bloody hate this fly by wire nonsense!
 
+1
Have you got the fault codesfrom a decent code reader? The loom is the likely culprit though as above. If you can get a good one from a breakers may be your best bet
If i can prove it's the loom i'll replace it with some trailer 7 core cable. I've tried using second hand before and it didn't work out too well... Throttle pedal, Then again it may be that i've got three good pedal: the first one, the ebay £12 one, and the brand new bloody expensive one if it IS the wiring...
 
Right then ladies and gents, here's the latest...

I bought some seven core cable to replace the existing loom between the pedal and the ECU.
Then realised that i only need FIVE wires, two doubled up at pedal end so bought some five core armoured cable.
Spent over a week waiting for a guy on here to reply with his Paypal details so i could buy some connectors and seals for both ends.
Gave up waiting and decided to solder my loom at each end.
Then today actually got into the job to discover that a previous owner has already done that...

So at the ECU end i cut into the joins to find four out of five are sound. Sound but not soldered the way i would have done it.
The fifth join when i'd removed the insulating tape and loom tape was hanging on by two strands of wire. By the time i'd held it up to take a pic it was down to ONE strand of wire and then when i'd put my phone back down it wasn't joined at all...
SO, out with the gas soldering iron, bared the piece from the ECU then tinned it then soldered it to the other part.
Re-wrapped all five connections then reconnected the two plugs into the ECU and the same at the pedal. Incidentally, there is signs of previous oil on the outside of the plug but dry inside and on the pins. The previous owner did say that he'd had the loom changed and everything cleaned.





The loom added is some seven core, and if i need to replace it shouldn't be an issue. I haven't checked the joins at the pedal end as they are all single wire to single wire joins and the iffy join was a single to double wire.

IMG_20200803_150557.jpg
IMG_20200803_144928.jpg


After reconnecting everything up i connected the Lynx to the OBD and cleared the faults. Then started the engine and revved it a bit for a while. I'll be honest, revving TD5 sounds nowt as nice as a racing car...
After i felt i'd annoyed the neighbours enough i rechecked the faults and found they'd all gone apart from

Driiver Demand 1 Out of range fault. Logged
Faults detected with driver demand. Logged
Can Error fault. Currently Active

So i had a play with the Lynx, cancelled the faults and tried some real time readings.
Off the top of my head, Driver 1 was around 0.86 on tickover and went up when i revved the engine.
Driver 2 and 3 started high and went down as revs rose.
When i rechecked faults i was down to

Can error fault. Currently Active.

Any ideas?
 

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Can error fault. Currently Active.

AFAIK, on Disco TD5, CAN bus is only relevant if you have automatic transmission, i.e. it is the communications link between the ECM and the EAT (electronic automatic transmission ECU). So if yours is a manual gearbox, I doubt if this is something that you ought to worry about. I am also not familiar with Lynx but some scan tools produce this type of error if they fail to detect the presence of a CAN bus or CAN devices during the discovery cycle.
 
Can error fault. Currently Active.

AFAIK, on Disco TD5, CAN bus is only relevant if you have automatic transmission, i.e. it is the communications link between the ECM and the EAT (electronic automatic transmission ECU). So if yours is a manual gearbox, I doubt if this is something that you ought to worry about. I am also not familiar with Lynx but some scan tools produce this type of error if they fail to detect the presence of a CAN bus or CAN devices during the discovery cycle.
Thanks for that. As it's a manual I'll stop worrying then :)
 
That's the one. I suggest you go through ebay. I did that and then he contacted me here and then never got back with payment details.
 
What length is needed for the new loom piece. Just thinking it might be worth making a few up and selling them on the Bay. Seems to be a common issue.

Is there a wiring diagram on the forum?

Just looking on Ebay, these are a connector made by Delphi, called a Metri-Pack 150. Also available from RS..
 
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What length is needed for the new loom piece. Just thinking it might be worth making a few up and selling them on the Bay. Seems to be a common issue.

Is there a wiring diagram on the forum?

Just looking on Ebay, these are a connector made by Delphi, called a Metri-Pack 150. Quite cheap when you take the "Land Rover" tag off them.
Look on the other link i gave you and read from the top. The OP has a diagram of sorts. I get the impression it's a common fault across all vehicles with a TD5. One of the other guys on the thread has a Defender.
I list two item numbers for both 5 core and 7 core in the other thread. I was originally going to use 7 core because there are 7 wires at the pedal end but two wires are joined together so only five go into the ECU.
I haven't bothered pulling out the wiring in mine because a previous owner has already replaced it. It looks like the problem with my Disco was one of the wires joined to a pair was down to only two strands of wire. I've rectified that now but at some point will replace all of the soldered connections at the ECU end and insulate them all using heat shrink and produce coldered joins that aren't about 10mm in width.
I haven't measured but i'd doubt you'd need more than a metre and a half from the pedal to the ECU using the same route as on mine. It goes through a grommet just above the main loom in the bulkhead and then up the wing just underneath the fuse box to the ECU.
loom arrowed.jpg
 
You wouldn't need a double plug like that.
First, it would be easier to poke it through the bulkhead grommet, and second the other end goes into the large black plug with about thirty different wires. You'd need to supply the wires with the correct seals and connectors on them.
Apparantly you can push out the existing wires using a small nail/screwdriver or large needle. You don't need to buy the tool i bought, and then didn't use...:)
IMG_20200803_160137.jpg
 
I'll take a look at mine. I have had a few "driver demand" faults logged, and once had it just cut to idle, until I restarted the engine.

So, am I right in thinking the loom from the pedal connects into the large multiplug on the ECU. (Not the red one) So , you would either need to add a female plug, spliced into the exisiting cables to add a replacement loom to the pedal, or the other option is to splice directly in to the existing cables with a soldered joint... Im just looking at options to look nice, and satisfy my OCD.
 
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Yes, the black one. You have a few options. Cut and replace the wires by either soldering them, using terminal blocks or replacing each wire individually into the plug by using either a five or seven core cable.
You do have to connect two pairs of wires together at some point between the pedal and the ECU as there are seven at the pedal but only five at the ECU.
In my case, i'm not happy with the insulation of the joins at the ECU end. I've just ordered a variety of different size heat shrink sleeving from ebay and at some point i'll be cutting out the existing joins and having only five at the ECU end insulated with heat shrink. Then i'll join the two pairs at the pedal end again using heat shrink. My reasoning being i WILL get the engine bay covered in crap and submerged, but hopefully not at the other end. The way the previous owner soldered the joins is bad too. The 'two into one' joins are nearly 10mm wide!
If you wanted to make them up to sell i suppose the most attractive method would be to sell them with the pedal plug connected with the correct pins connected to the ECU end with seals already in place and tell the buyers to feed the cable through the bulkhead grommet from the pedal end and then to remove the apropriate pin at the other end and push the correct new one into it's place.
As long as you include a drawing showing the correct position you should be alright.
One person mentions in the other thread that the pin numbers the OP quoted were wrong in his case. I don't know if the other guy had a Defender and the pin numbers differ between Disco and 'Fender or not?

I was going to use the five core armoured cable and modified the OP's diagram for my use. My five wires are black, numbered one to five and a green and yellow wire.
I'd be inclined to check the wire colours are the same on all TD5 pedal/ECU looms. If they are then all you'd have to do is state that 'black #1' is white/green. 'Black #2' is white/grey and so on. That way all they have to do is remove that coloured wire and push the new one in it's place.
It would be safer than saying put 'black #1' into pin 12 if pin 12 happens to be blue and the wrong wire...
Pedal plug wiring.JPG


Of course just replacing the wiring doesn't guarantee to fix the problem. It COULD be the electronic pot on the side of the pedal...
Mine started with a refusal to rev. So i switched off and on again and all was well for about six months. Then it happened again a few times. Then the last time i was driving to work half a mile from the M5 exit and it stopped revving.
OH CRAP!!!
Off and on, off and on and i managed to make it up the off ramp and most of the way around the roundabout. The off and on three or four times got me across the next roundabout but no further so i pulled off the road onto the grass and talked to it nicely.
Then it played ball and i managed to pull up outside work.
I came out of work at half ten at night thinking i'd just switch off and on again when needed to drive the eleven miles home. NO!
It didn't rev again. So i drove home on tickover. What would normally take me a leisurely twenty minute drive took a little bit longer. I left work just gone half ten and pulled up outside home at five to midnight.
Onto the forums and mostly everyone said pedal!
SO i looked at ebay then thought it could be cheap, but might be as reliable as the one on my car so i looked at the price for a new one.
Got up off the floor and paid £12 for a second hand one.
That lasted three weeks.
So then forked out £252 for a new one!
And i bet i haven't driven the car 200 miles before i wound up where i am now.
So just a word of warning, it MAY be the wiring, on the other hand it may NOT.
 
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