Member Since: 02 Nov 2015
Location: Pretoria
Posts: 9
Run, cut out x 6, then stays off
I have a 2005 TDV6, cleaned the engine (taking care not to get water in battery box), took the car for a drive, all okay, parked the car then an hour later hazards came on by themselves, when I opened the door the dash (radio, fan, display etc) was on even though the ignition was off. Disconnected and charged battery, next day car starts for about 2 seconds, revs up normally, cuts for half a second, runs for 2, cuts for half, rhythmically for 6 times then cuts finally. If i pull and refit fuse 27 (ecu) the procedure is reset and repeats itself. Even if I don't start, just switch ign to pos 2 the relays 8 (fuel pump) and 6 (ecu) can be heard clicking on for 2 seconds, off for 0.5 seconds. Car has been standing in dry, warm weather for more than a week now. Ecu codes: P0562 system voltage low, P0a09 DC DC converter voltage low, P060A ecu internal monitoring, P0087 fuel rail pressure low. The all seem like symptoms of the relays switching off rather than the cause???? Any one with similar experience?
2nd Nov 2015 9:34 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
You have a fault on the CANBUS - either a wiring issue or one of the systems on the CANBUS network.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 02 Nov 2015
Location: Pretoria
Posts: 9
The coonnectors and pins of the ecu all look perfect, checked canbus voltage (2.35V on pin14, 2.65 on pin 6 of OBD) and resistance (60 Ohm pin 6 to 14 battery disconneted), had an Autologic scanner on the car today, tried to reflash ecu - no change. I dont know whether the voltage error codes are a result of the main relay switching the ecu off while engine is running or the cause thereof. Same goes for the fuel rail pressure code (P0087). Does anyone have experience of a bad rail pressure sensor\regulator? What are the symptoms?
3rd Nov 2015 7:18 pm
narked50
Member Since: 16 Nov 2015
Location: Gloucestershire
Posts: 4
Hi, I have exactly the same problem. Started with the transfer box not working properly, then lots of warning lights and the engine only starting for a second or two. Vehicle went through some deep water 2 years ago. Transfer box ecu had on pin corroded away completely. Have replaced transfer box ecu, but this has had no effect. Any help would be welcome.
16th Nov 2015 6:28 pm
barendjoubert
Member Since: 02 Nov 2015
Location: Pretoria
Posts: 9
I'm still battling with this problem, seems like it might be immobiliser related (possibly communication between bcm and ecm)???
16th Nov 2015 7:50 pm
narked50
Member Since: 16 Nov 2015
Location: Gloucestershire
Posts: 4
I think that the engine ecu is getting an unacceptable reading from somewhere and shuts everything down. I can keep engine going for about 30 secs if I pump the throttle. Will try and have a further look today.
17th Nov 2015 10:22 am
longclose
Member Since: 07 Mar 2015
Location: Dorset UK
Posts: 234
No expert on the D3, but I would do along with Mikey on all of the above but focus in on earth connections. Those error codes without doubt indicate a resistance to earth or on the 12V supply side of the ECU, have seen this on D2's in the past on the SLABS ECU, it turned out to be a dry joint on the main chassis connection from the negative tail from the battery logging low voltages faults in the ECU's.
The ECU will have multiple supplies and earths, the voltage will drop when the ECU is powered up so it will be quite difficult to locate. I would be very surprised if it was an ECU failure/failing get the wiring diagram and check them out individually. It of course could be relays or the relay connections.
Also just for the sake of it use the hidden menus on the Nav and/or radio to get the voltages when all systems are powered up. If low <11.0V work your way back to the main chassis connections, if OK it will likely be localised to the ECM/PCM.
http://www.disco3.co.uk/forum/topic45443.htmlOwning a Discovery 3 is like dating a model.. a firm body and shape, wow.. the ride is fantastic > for this your wallet can take a pounding and you worry about being deflated at any time...
2009 Model D3 HSE
22nd Nov 2015 8:26 am
barendjoubert
Member Since: 02 Nov 2015
Location: Pretoria
Posts: 9
I have checked all the basics, all okay. On an Autologic it gave an error code that the ecu does not get proper authorisation from the bcu. The bcu does enable the starter, so its happy with the key. Its as if the sincronisation between ecu and bcu went out all by itself??? Communication with all the control units via the diagnostic plug works and the canbus tests okay. If I switch the ignition on, the immobiliser LED on the rev counter keeps blinking the same way when the ignition is off.
23rd Nov 2015 8:35 pm
longclose
Member Since: 07 Mar 2015
Location: Dorset UK
Posts: 234
Having spent some time in automotive electronics, the processor memory should be resilient to what is known as "brown out", this is where the processor is delivered a voltage under specification and should protect its FLASH memory. The truth of the matter is that this is extremely difficult to make 100%. It is therefore possible from the errors that you previously provided (ECU low voltage) that the FLASH memory has become corrupted during "brown out reset" and lost its sync with the BCU.
I suggest a complete re-flash and re-configuration of the ECU/PCM with re-synch to the BCU, I am not an expert in this area and am learning very slowly to avoid SWAMBO disappointment syndrome..
I am sure the that the guys on this forum will give you the steer to undertake this process, however I am concerned that you have still yet to find the route cause of the earlier DTC's
Good luck.. Owning a Discovery 3 is like dating a model.. a firm body and shape, wow.. the ride is fantastic > for this your wallet can take a pounding and you worry about being deflated at any time...
2009 Model D3 HSE
25th Nov 2015 7:10 pm
barendjoubert
Member Since: 02 Nov 2015
Location: Pretoria
Posts: 9
Thanks for the good info, longclose. Yes, the are, at least according to the recurring DTC's, possiply more faults and it seems like canbus communication may not be 100% but some DTC's relating to canbus communication were present even when the vehicle ran well without any malfuntion symptoms. I suppose the real chalenge is not reading DTC's but interpreting them. Another chalenge is that many diagnostic systems give good codes on most systems on these D3's except on the immobiliser\alarm\key recognition. The Autologic sytem works well on the immobiliser and we tried to reprogram the ECU and syncronise it with the bcu but to no avail (the Autologic goes through the process and all looks okay but afterwards the engine still doesn't run and log a dtc indicating immobiliser mismatch). Since the ecu and bcu are vin-locked I wonder if that is perhaps what prevents us to re-syncronise these???
25th Nov 2015 9:32 pm
Disco_Mikey
Member Since: 29 May 2007
Location: Dundee, Scotland
Posts: 20727
It the car is immobilised, the crank function is inhibited...My D3 Build Thread
Member Since: 07 Mar 2015
Location: Dorset UK
Posts: 234
That's interesting Mikey.. I guess the next question is does the ECU have to have an ongoing sync with the BCU to maintain the engine running? On the TD5 you had a mobilised/immobilsed screen, as I say complete novice on the D3 so just grasping at straws.
barendjoubert are the earlier low voltage messages still appearing as on your first post?Owning a Discovery 3 is like dating a model.. a firm body and shape, wow.. the ride is fantastic > for this your wallet can take a pounding and you worry about being deflated at any time...
2009 Model D3 HSE
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for this your wallet can take a pounding and you worry about being deflated at any time...
