Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
Electrical gremlins and Battery drain - Progress
I have been trying to track down a number of electrical problems for a little while now and have read many of the posts on here. I was hoping if I put some details on here some of the Discovery Gurus may be able to point me in the right direction.
Battery drain
Using Robbie's excellent tutorial I have determined that I have a permanent 1.3 amp draw on the battery, this starts off at 5 amps when first locked and declines to 1.3 amps after about 20 minutes then remains at 1.3A however long I leave it. Again using the tutorial I have tried to identify the source of the drain, there is no current draw on the wire to the starter/alternator wire it is all on the wire to the BJB. I have managed to put a digital multi meter across all the under bonnet fuse test points and all except fuses 67, 68 and 69 under the dash - how does anyone get a probe on these last 3 fuses?
I have found the following voltage drops
Fuse, Value (A), Volts, Current (A),
39, 5, 0.002, 0.113,
53, 15, 0.001, 0.218,
54, 5, 0.001, 0.056,
Total 0.387
So I have found approximately a third of my escaping amps, any ideas where to go next?
I also have the following fault codes
Vehicle scanned on 24-03-2015 12:46
Using IIDTool BT V3.0 B1262
Body Control
•B1A59-16 (2F) Sensor 5 volt supply circuit - General electrical failure - circuit voltage below threshold
•B1B85-49 (2F) Memory control module - System internal failure - internal electronic failure
•B1C13-3A (2F) Driver's up/down mirror motor feedback circuit - Frequency modulation/pulse width modulation failure - incorrect, has too many pulses
•B1C14-3A (2F) Driver's left/right mirror motor feedback circuit - Frequency modulation/pulse width modulation failure - incorrect, has too many pulses
•B1C15-3A (2F) Passenger's up/down mirror motor feedback circuit - Frequency modulation/pulse width modulation failure - incorrect, has too many pulses
•B1C16-3A (2F) Passenger's left/right mirror motor feedback circuit - Frequency modulation/pulse width modulation failure - incorrect, has too many pulses
Is there any chance that these are related to the battery drain issues?
Thanks in advance for any suggestions anyone out there may have.
1997 Defender 90 for the kids and I to have a go at some competitive off road RTV and Tyro trials, daughter picked up her first trophy over the August Bank Holiday.
Previous Land Rover history
1996 P38 4.6 V8 Autobiography
1996 Discovery TDi 300
1972 Range Rover 3.5 V8
LWB Hard Top Series 3
LWB Truck Cab Series 2A
Not been without a Land Rover for over 40 years - I must need therapy!
Last edited by MGCarr on 18th May 2015 8:32 pm. Edited 1 time in total
25th Mar 2015 9:53 pm
MGCarr
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
For the sake of completeness I should mention that I also have intermittent loss of sport mode and command shift and permenant loss of special programs and a traction reduced warning every time I start up but I have up to now assumed that these were a consequence of the battery drain
1997 Defender 90 for the kids and I to have a go at some competitive off road RTV and Tyro trials, daughter picked up her first trophy over the August Bank Holiday.
Previous Land Rover history
1996 P38 4.6 V8 Autobiography
1996 Discovery TDi 300
1972 Range Rover 3.5 V8
LWB Hard Top Series 3
LWB Truck Cab Series 2A
Not been without a Land Rover for over 40 years - I must need therapy!
25th Mar 2015 11:13 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
Well done for getting this far.
I agree the weak battery will have probably triggered the loss of special programs / traction control. Not seen a weak battery cause loss of command shift though, but not saying that it cannot happen….
The 3 circuits you have identified I would expect to have some current flow even when asleep (alarm, audio head and memory module). Some multimeters do not have a dedicated mV or microvolt range so there may be accuracy and count issues in your readings which may or may not explain their apparent elevated levels. You can check this by using the DMM in the traditional amps mode and using it to replace one of the 5 amp measured fuses, letting the vehicle sleep and comparing the 2 readings.
The fault codes grab my attention as this circuit is live even when the vehicle is asleep. A stuck input or fault can draw more power than you would wish.
It may not be a valid test but I would be minded to remove CJB fuses 46 & 54 that power the memory control module and see if the vehicle will sleep and see what the new overall current draw is.
Good luck.Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
Robbie
Thanks for the suggestions I will try them tomorrow, weather permitting, also thanks for reminding me that my DMM has a mv scale, I am so used to selecting the 20v scale that displays to 3 decimal places I completely forgot about the dedicated mv scale duh .
I will retest the 3 circuits again.
1997 Defender 90 for the kids and I to have a go at some competitive off road RTV and Tyro trials, daughter picked up her first trophy over the August Bank Holiday.
Previous Land Rover history
1996 P38 4.6 V8 Autobiography
1996 Discovery TDi 300
1972 Range Rover 3.5 V8
LWB Hard Top Series 3
LWB Truck Cab Series 2A
Not been without a Land Rover for over 40 years - I must need therapy!
26th Mar 2015 9:57 pm
MGCarr
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
Robbie
It sounds like we both had an afternoon of fuse probing and amp clamping, following your suggestions I retested fuses using the millivolt scale on my dmm and got the following slightly different readings
Fuse 39 5 amp fuse 2.0 mv 113 ma
Fuse 53 15 amp fuse 2.2 mv 480 ma
Fuse 54 5 amp fuse 1.1 mv 62 ma
Total 655 ma
But the draw at the lead to the BJB is still 1.4 amp
So I then woke the car up and removed fuses 46 and 54 from the CJB and locked the car and let it go back to sleep, after about 30 minutes the current draw at the wire to the BJB dropped to 160 ma, a significant step in the right direction. So it looks like your suggestion that the fault codes relating to the seat memory module were critical was spot on. What I find puzzling is that the current reduction at the BJB is more than twice the current that I had measured at the fuses. I think my next step is to strip the driver's seat base out and see if that allows me to get to the wires at the back of the seat memory module and see if that sheds any further light on the problem.
Any further suggestions you might have would be most gratefully received.
John
1997 Defender 90 for the kids and I to have a go at some competitive off road RTV and Tyro trials, daughter picked up her first trophy over the August Bank Holiday.
Previous Land Rover history
1996 P38 4.6 V8 Autobiography
1996 Discovery TDi 300
1972 Range Rover 3.5 V8
LWB Hard Top Series 3
LWB Truck Cab Series 2A
Not been without a Land Rover for over 40 years - I must need therapy!
27th Mar 2015 10:25 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
When you have disabled components remember to do a complete ignition cycle (including start) and then allow the full 30 mins or so for the vehicle to sleep.
If you are lucky the problem with the driver's seat, when resolved, may allow the AHU to sleep. But the AHU current draw is, as yet, unexplained. The vehicle does do some strange things when individual modules have issues or faults.
I've added an update to my guide after the opportunity afforded by Dented Disco's vehicle. Your results are promising and a drop to 160mA is a significant step in the right direction.
Good luck.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
500ma down only 850ma to go
A brief update, progress has not been as swift as I might have hoped as the foul weather has not been conducive to working on delicate electrical systems in the open on the drive but over the weekend I did get enough breaks in the weather to trace the wiring from the CJB to the Seat Memory module. The ammeter showed that I had about an 800ma current all the way down to the SMM with the car in sleep mode and no visually apparent damage to the wiring, this combined with the previously mentioned fault codes convinced me it was worth buying a new module.
The new module arrived today and I fitted it and cleared the existing fault codes, rescanned and got this
Vehicle scanned on 31-03-2015 15:35
Using IIDTool BT V3.0 B1262
No fault codes !!!!
I have never actually seen that before on this car.
I then locked the car and let it go to sleep in order to check the battery current drain, after 35 minutes it showed 890ma draw on the wire to the BJB , still the same after an hour. A bit disappointing but not entirely surprising as I had suspected that there might be more than one underlying fault.
Now this is where it all gets a bit 'one step forward two steps back' because I rescanned for faults and got the following
Vehicle scanned on 31-03-2015 17:35
Using IIDTool BT V3.0 B1262
Instrument Pack
•U0159-87 (2E) Lost communication with parking assist control module - Bus signal/message failure - missing a message
Transfer Case
•P1811-00 (2F) Four-wheel drive low ratio - short circuit to ground
•P1807-00 (2F) Four-wheel drive high ratio - short circuit to ground
•U0132-86 (2E) Lost communication with ride level control module - Bus signal/message failure - signal is invalid
•U0100-87 (2E) Lost communication with engine control module/ powertrain control module 'A' - Bus signal/message failure - missing a message
•U0128-87 (2E) Lost communication with parking brake control module - Bus signal/message failure - missing a message
•U0155-87 (2E) Lost communication with instrument cluster control module - Bus signal/message failure - missing a message
•U0126-87 (2E) Lost communication with steering angle sensor module - Bus signal/message failure - missing a message
•U0122-87 (2E) Lost communication with vehicle dynamics control module - Bus signal/message failure - missing a message
•U0101-87 (2E) Lost communication with transmission control module - Bus signal/message failure - missing a message
•U0138-86 (2E) Lost communication with all terrain control module - Bus signal/message failure - signal is invalid
Transmission
•P081C-00 (6D) Unknown
I have been following with interest Robbie's posting on Dented Disco' thread and in an act of blatant plagiarism I have made up some slightly more primitive sets of 'fuse buddies' for the power fuses and weather permitting I will be testing those tomorrow.
1997 Defender 90 for the kids and I to have a go at some competitive off road RTV and Tyro trials, daughter picked up her first trophy over the August Bank Holiday.
Previous Land Rover history
1996 P38 4.6 V8 Autobiography
1996 Discovery TDi 300
1972 Range Rover 3.5 V8
LWB Hard Top Series 3
LWB Truck Cab Series 2A
Not been without a Land Rover for over 40 years - I must need therapy!
1st Apr 2015 12:11 am
MGCarr
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
Above are my poverty model copy of Robbie's fuse buddies for the fusible links without test points, I made up 10 wires with an insulated female spade terminal crimped on one end and a male spade terminal crimped on the other end. This meant that I could test 5 fuses each time I let the car go to sleep.
With the clamp on ammeter all fuses showed a small number of milliamps which is something I will come back to later. The really interesting finding was that FL3 was showing a current draw of around 890ma, almost exactly the drain I am looking for. Looking at the diagram on the fuse box lid, which is two interlocking cog wheels, I am assuming this relates to the transfer box.
Then I may have got lucky because as I disconnected the fuses getting ready to set up for testing the next batch of 5 I disconnected FL3 while the car was still in sleep mode and heard a distinct clunk from under the car which sounded very much like a substantial solenoid disengaging and on reconnecting and checking with the amp clamp the current draw had dropped away to almost nothing. When I started the car the infamous 'traction reduced' warning had disappeared and the various terrain response programs could be selected, unfortunately after 3 or 4 engine stop start sequences the problem returned. So I am starting to think that either the solenoid is sticking mechanically or I have something electrical which is refusing to disconnect the solenoid.
Does anyone know which of the terrain response programs actively lock the centre differential? or does it only lock when wheel speed difference is observed?
Has anyone any suggestions as to what might be causing the solenoid to remain engaged?
Going back to my earlier comment about all of the fuses showing a small current draw when using the clamp on ammeter, I cross checked them by checking the voltage drop across the terminals of my fuse buddies and found there to be 0 volts - see picture.
As you can see in the picture the DMM is reading 0mv but the amp clamp is reading 33 ma, I am hoping one of the electrical Gurus on here can advise whether it is a competence issue on my part, a fault on the ammeter or is it possible that it is something like RF induced current. We do have a significant problem with RF interference at the moment, for example 2 of our cars cannot be locked or unlocked with the remote keys when on the drive but are perfect everywhere else.
Sorry about the length of this but hopefully bits of it may help others and as always any hints tips or suggestions will be gratefully received
1997 Defender 90 for the kids and I to have a go at some competitive off road RTV and Tyro trials, daughter picked up her first trophy over the August Bank Holiday.
Previous Land Rover history
1996 P38 4.6 V8 Autobiography
1996 Discovery TDi 300
1972 Range Rover 3.5 V8
LWB Hard Top Series 3
LWB Truck Cab Series 2A
Not been without a Land Rover for over 40 years - I must need therapy!
1st Apr 2015 11:18 pm
waterbuoy
Member Since: 26 Oct 2013
Location: Argyll
Posts: 2894
Commendable effort so far
Imay be corrected on this, but I was under the impression that only rock-crawl mode activates the diff-lock?Currently 2009 Disco 3 SE, 2013 MY D4 HSE and 2016 D4 SE
Previously:
TD5 Defender 110 CSW (230k miles)
300TDi Disco 1 (289k)
4 RR Classics (300-350k each, 2 manual, 2 auto)
110 V8 CSW (220k)
S3 109 hi cap pickup (ex RN)
S2A 88 Safari SW with lpg conversion (bloody lethal)
1st Apr 2015 11:28 pm
MGCarr
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
Thanks Waterbouy, I was hoping one of them did in order that I can try engaging and disengaging the diff lock a few times to see if that frees anything off.
1997 Defender 90 for the kids and I to have a go at some competitive off road RTV and Tyro trials, daughter picked up her first trophy over the August Bank Holiday.
Previous Land Rover history
1996 P38 4.6 V8 Autobiography
1996 Discovery TDi 300
1972 Range Rover 3.5 V8
LWB Hard Top Series 3
LWB Truck Cab Series 2A
Not been without a Land Rover for over 40 years - I must need therapy!
1st Apr 2015 11:44 pm
highlands
Member Since: 11 Jan 2010
Location: NW Highlands
Posts: 5098
Don't know about the solenoid but you could extend the legs on the fuse buddies to put a few coils of the wire into the clamp to help improve accuracy.
Oh, presumably you're zeroing the current measurement before taking readings?Black 05 TDV6 HSE Auto
Grey 05 TDV6 HSE Auto (Gone)
54 TDV6 SE Man (killed by me )
Last edited by highlands on 2nd Apr 2015 12:20 am. Edited 1 time in total
2nd Apr 2015 12:06 am
highlands
Member Since: 11 Jan 2010
Location: NW Highlands
Posts: 5098
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
Thanks for the suggestions Highlands, especially the bit about the Wiki, for some reason I always forget that it is there
1997 Defender 90 for the kids and I to have a go at some competitive off road RTV and Tyro trials, daughter picked up her first trophy over the August Bank Holiday.
Previous Land Rover history
1996 P38 4.6 V8 Autobiography
1996 Discovery TDi 300
1972 Range Rover 3.5 V8
LWB Hard Top Series 3
LWB Truck Cab Series 2A
Not been without a Land Rover for over 40 years - I must need therapy!
2nd Apr 2015 12:33 am
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
MGCarr wrote:
As you can see in the picture the DMM is reading 0mv but the amp clamp is reading 33 ma, I am hoping one of the electrical Gurus on here can advise whether it is a competence issue on my part, a fault on the ammeter...
Sorry about the length of this but hopefully bits of it may help others and as always any hints tips or suggestions will be gratefully received
Well done!
I've not come across the issue you have found so I will give it some thought when I have a moment.
Regarding the undetectable mV across the big fuse, this is due to the very low resistance across this big link and the very low current in the circuit. Effectively the voltage drop is too small to be measured with a DMM so cannot be used as a test method on this type of fuse.
I'm sure many will be grateful for the long post and the pictures as it removes some of the mystery around electrical diagnosis; it well help and encourage others.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 08 Nov 2005
Location: Surrey
Posts: 217
Hi.
Just a long shot...but have you tried running an earth from the battery to the gearbox? It could be just a bad earthing somewhere. Some relays rely on a good earth to release themselves.
Probably wrong!!
Good luck with it - I sincerely hope you get it fixed, after all of your hard work.
Cheers.
MGMG
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Buckingham Blue
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