Disco 2 Auto Disco II cranks but will not start 3 Amigo's + M&S flashing!

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Neptune19522

Active Member
Posts
108
Location
Warwick
Drove 76 miles then six hours later turned the key, cranked well but no start. M&S light and the three Amigo's flashing. Checked the Crank Sensor with a oscilloscope and got a good signal. RAC chap sent an e-mail of faults - CAN bus error and Gearbox position switch error. Had a spare switch but no improvement. ECU red connector oil was washed out but still no start. Inertia circuit is good. Fuel pump works if relay closed manually but not working on cranking. All engine relays changed, all fuses intact, no apparent damage on harness just will not fire. I do have some hi temp wire and probably all the connectors to make an injector harness but before that has anyone got any ideas?
Retired Land Rover electrical Project Development employee and lots experience with wiring harness; so happy to change any connectors or pins, which I have, but which pins need cleaning / replacing? Any one got any ecperance or similar problems and perhaps the cure...
 
Neptune19522 said:
Drove 76 miles then six hours later turned the key, cranked well but no start. M&S light and the three Amigo's flashing. Checked the Crank Sensor with a oscilloscope and got a good signal. RAC chap sent an e-mail of faults - CAN bus error and Gearbox position switch error. Had a spare switch but no improvement. ECU red connector oil was washed out but still no start. Inertia circuit is good. Fuel pump works if relay closed manually but not working on cranking. All engine relays changed, all fuses intact, no apparent damage on harness just will not fire. I do have some hi temp wire and probably all the connectors to make an injector harness but before that has anyone got any ideas?
Retired Land Rover electrical Project Development employee and lots experience with wiring harness; so happy to change any connectors or pins, which I have, but which pins need cleaning / replacing? Any one got any ecperance or similar problems and perhaps the cure...
Click to expand...
Hello and welcome!

Firstly, do you have a Nanocom/foxwell etc? The CAN bus error means the autobox can't communicate with the engine ECU, ignore the position switch error, that won't stop it starting if it cranks. The pump relay is controlled by the engine ECU also so it is possible that the engine ECU is immobilised, even though the BCU isn't (or it wouldn't crank).

Can you get diagnostics from the engine ECU rather than the gearbox ECU which your fault codes seem to come from? Is the temperature gauge behaving normally, also driven from the engine ECU? No fault with the injector harness would stop the pump relay closing, so you can probably ignore that one for now. Ignore the three Amigos for now also. It is pointing to the engine ECU, or power to it.

Cheers.
 
Thanks for your comments I will try them all tomorrow - I am retired so time is not a problem.

I do not have any diagnosis kit of any sort - yet! That is tomorrows task. All fuses are intact but I have not checked the supply to the ECU to date. I have 'found' my spare SLABS ECU so that might switch off the three Amigos, but the M&S lights have been coming on for some time almost as soon as the engine started, when it did... This condition is getting worse. One v stupid thing I did was to change down into 3rd when driving through a town but forgot in was in '3' when I drove out of that town at about 70mph; I cannot see the M&S lights unless I lean forward to deliberately see them. I wonder if this set of some sort of internal DTC? My computer savvy niece, who has a diagnostic program on her laptop, tried to clear all the faults but there was two that she could not switch off! The comments about the CAN bus is concerning but the circuit diagrams have no CAN bus drawings

Also I have just unplugged the injector harness from the engine and lots of oil - big clean up tomorrow; might even try and make a new harness!
Regards
 
Neptune19522 said:
Thanks for your comments I will try them all tomorrow - I am retired so time is not a problem.

I do not have any diagnosis kit of any sort - yet! That is tomorrows task. All fuses are intact but I have not checked the supply to the ECU to date. I have 'found' my spare SLABS ECU so that might switch off the three Amigos, but the M&S lights have been coming on for some time almost as soon as the engine started, when it did... This condition is getting worse. One v stupid thing I did was to change down into 3rd when driving through a town but forgot in was in '3' when I drove out of that town at about 70mph; I cannot see the M&S lights unless I lean forward to deliberately see them. I wonder if this set of some sort of internal DTC? My computer savvy niece, who has a diagnostic program on her laptop, tried to clear all the faults but there was two that she could not switch off! The comments about the CAN bus is concerning but the circuit diagrams have no CAN bus drawings

Also I have just unplugged the injector harness from the engine and lots of oil - big clean up tomorrow; might even try and make a new harness!
Regards
Click to expand...
I don't think anything you have done while driving could cause this. Mine flashes M&S from time to time due to the position switch, I have a Nanocom and just reset the code.

I don't believe the TD5 is fully OBD compliant therefore there is only a limited amount you can do with a generic tester and @sierrafery (the world expert:)) will tell you unless you get a dedicated diagnostic, you will be lied to.

The CAN bus is on C0158 (the ECU red one) pins A32 and A35. A CAN bus error won't stop it starting, it is reported by the autobox ECU. This error again points to the ECU in a sulk and not wanting to play. It's worth checking F24 in the passenger compartment fuse box that it is OK and you get power when the ignition is turned on.

Good luck.
 
I did check all the pass FB fuses this morning and indeed took the UB FB out to chase the inertia SW circuits so all fuses are intact. The only harness damage I have observed was oil in the red connector and in the injector connector; the red is now clean but the injector con' will be cleaned tomorrow. The engine seems to have rather too much oil leaking out of various parts - this week was meant to be oil change and track rod end replacement, (MoT chap gave me a warning for them but I cannot see any problem), but then it would not start. Experience tells me that lots of unrelated symptoms usually have one simple cause; just a matter of finding it...

I have found the CAN bus on the circuit diagram and it only seems to go to the EAT ECU; I might check those for continuity.

The confusing thing is I drove to the car park and then six hours later it would not work - very perplexing!

Re a diagnostic devise I am open to suggestions!
 
Neptune19522 said:
I did check all the pass FB fuses this morning and indeed took the UB FB out to chase the inertia SW circuits so all fuses are intact. The only harness damage I have observed was oil in the red connector and in the injector connector; the red is now clean but the injector con' will be cleaned tomorrow. The engine seems to have rather too much oil leaking out of various parts - this week was meant to be oil change and track rod end replacement, (MoT chap gave me a warning for them but I cannot see any problem), but then it would not start. Experience tells me that lots of unrelated symptoms usually have one simple cause; just a matter of finding it...

I have found the CAN bus on the circuit diagram and it only seems to go to the EAT ECU; I might check those for continuity.

The confusing thing is I drove to the car park and then six hours later it would not work - very perplexing!

Re a diagnostic devise I am open to suggestions!
Click to expand...
Yes, the CAN bus is only between the ECU and the EAT ECU. A problem here wouldn't cause non-starting, it is a symptom of the problem, probably.

Re the oil leak, check the cam blanking plug at the front of the engine - the O-ring goes hard and they leak a lot of oil which is then blown back over the engine, into the alternator and everywhere. Don't ask how I know that one..... The rocker cover gasket is another favourite also.

For diagnostics, the Nanocom is expensive and the Foxwell seems to do almost everything but much cheaper. I can't give advice as I have only used the Nanocom, but the Foxwell has many supporters here. And there are others....
 
Hi. First of all measure voltage while cranking cos if you had a charging issue and the battery got weak that's the probem, also there are several CAN-bus fault codes, it's important to know which one you have .... where did you check the crank signal with oscilloscope? on the sensor or in the ECU plug? also are you sure how that signal should be?
 
The perplexing thing is the problem generated a fault when the vehicle was parked. How did I drive to that car park but was unable to drive away? A fretted wire or oil creating an open circuit would seem to be the answer but again it's a matter of finding that short or open circuit. A Wheatstone bring or better still a harness drawing would help. Frustratingly I know the chap who drew that harness drawing, in fact the whole D2 harnesses!
Thank you for giving me a starting point regarding diagnostic tool. I was hoping to get something that I could use on my 88" - which has several Def items in it including a diagnostic connector!
 
Crank signal was first tested with the sensor in my hand stood next to my vehicle and oscilloscope! Then after reinstalling it I used some IDC prob's directly on the red connector. Both situations showed a very strong signal. I do not think the battery is the problem as it turns the engine over very well; it has also been charged and left overnight to soak, not connected to vehicle or charger, and returned 12.93V next morning. OK not conclusive but indicative! The battery is also less than a year old.
 
You need to see the voltage while cranking cos if it drops below 10.5V all the other things are futile the crank signal strenght is relevant only by reading what the ECU gets after the ADC and that's visible only with diagnostic tool, the oscilloscope test confirms only that the sensor is not dead and that the circuit is OK
 
All and any help would be greatly received. I am in no way intending to denigrate any person who is trying to help me however I am frustrated with this problem; my usual answer would be to go and chat directly with the engineer who was responsible for the component. Can't do that any more.

I acknowledge the problem of pulling the battery down I just have not thought of checking it until you gave it a figure. However tomorrow I will set up that test after I have cleared some of the oil out of the injector harness connector.
 
Neptune19522 said:
Thank you for giving me a starting point regarding diagnostic tool. I was hoping to get something that I could use on my 88" - which has several Def items in it including a diagnostic connector!
Click to expand...
I am hoping someone else will jump in here with advice on the diagnostics. If you want to cover other vehicles, the Foxwell will do many more than the Nanocom. It was even of use for @Stanleysteamer 's Citroen. Whether it covers the 88", I don't know.

I bought my D2 4 years ago, my first ever Land Rover and as it was cheaper than I wanted to spend to get a really good one, I spent the difference on a Nanocom. I've not regretted it (in spite of its many quirks) and have dedicated diagnostics for my wife's Peugeot anyway.

Good luck.
 
It could be the battery; it is not unknown but it is vary rare.

The three Amigos appear at switch on as does the M&S lights; then extinguish; nothing unusual there. Then the M&S light up and start to flash and two of the Amigos light up then the third, hight sensor I think, the RH one anyway, come on and cranking is possible but of course no start. The main relay, R9, comes on but the other two, fuel and engine, R6 and R1, do not engage. Manually pressing R1 produces the sound of the fuel pump running but this needs to be proved by cracking the fuel supply pipe to the injectors - carefully - for 100% confidence that the pump is in fact working correctly.
I am convinced that something has set a fault flag and is prohibiting the engine ECU from exciting the R6 and R1 relay hence no start. I will be purchasing a diagnostic tool to prove this however I would like to be able to set up the 10AS in my 88" and a projected build of my 109.5" (documents say Series 2A but its on a 110 chassis now...).
 
To eliminate the battery as a cause, can you not simply jump it with another battery which would deffo give you the necessary voltage to start it if that is the only problem?
And while we are on looms, although this may have nothing to do with your problem, the loom that goes through a P clip on top of the transmission box is a well-known weak point, at the clip, where it wears and can lead to at least some of what you are seeing. This is often intermittent and very had to see unless you remove it and really poke around.
But that's for later!
Best of luck with solving it!:):)

(And yes I do thoroughly recommend the Foxwell!;))
 
Thanks for your advise re the batterie. It must stand on it's own as causing it to start in the garage would only prove it has failed. I do think the existing battery is OK as it spins the engine with ease but it just does not start.

Getting to that clip may be an act of desperation as I may have to take the gear box out to effect any required cure but if that is the fault then out it comes!

Also thanks for the recommendation of a useful diagnostic tool.

When, note when not if, I cure this problem I will attempt to write it up for any future D2 owners who have this problem. Thanks to all those who have given me new ideas and reinforced some of my own ideas in the attempt to cure this frustrating problem.
 
Yes; as that is a well known reset mode. I also lock and unlock the vehicle each day before I set about seeking a cure of this problem, but thanks for your interest.
 
Neptune19522 said:
Thanks for your advise re the batterie. It must stand on it's own as causing it to start in the garage would only prove it has failed. I do think the existing battery is OK as it spins the engine with ease but it just does not start.

Getting to that clip may be an act of desperation as I may have to take the gear box out to effect any required cure but if that is the fault then out it comes!

Also thanks for the recommendation of a useful diagnostic tool.

When, note when not if, I cure this problem I will attempt to write it up for any future D2 owners who have this problem. Thanks to all those who have given me new ideas and reinforced some of my own ideas in the attempt to cure this frustrating problem.
Click to expand...
I'd still swap the battery with a known good one.
And the part of the loom can be removed without taking the box off, but as I said I don't think this is your problem, or not the main one. It hasn't been known to stop the car starting, at least not as far as I am aware. More likely to throw up M & S flashing lights, limp home etc.
Best of luck!
 
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