Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
Thanks MG and Robbie for the suggestions and the wiring diagrams, I have checked the earthing strap from the back of the transfer case to the body and that is OK, I have not had chance to run a direct earth back to the battery as my mate borrowed my long heavy duty jump leads so that is on tomorrows to do list.
I have had the Transfer case control module out and there is no sign of corrosion or any bent pins, I have carefully opened up the case and cannot see any sign of water ingress in there, so the plugs and sockets have had a good spray with contact cleaner and it is all back together, however I have my suspicions that I might be revisiting it.
I have done some testing of the bundles of wires going down to the transfer case and with the car in sleep mode the wires leading to the unit on the second of Robbie's wiring diagrams, marked Motor-Transfer box M276, is showing a current draw of similar magnitude to the one I am seeing at FL3. If I disconnect this lead the current draw at FL3 drops from 890ma to just over 200ma but still never goes completely to sleep, hence my suspicions that I will be revisiting the control module.
I have checked the voltages at the terminals of the lead to the transfer box motor and get the following readings
Brown 6.65v
Green/red 9.19v
Red/Yellow 0.00v
Thick Red 0.00v
Green/yellow 9.19v
Blue/red 9.65v
Thin red 4.97v
I have taken all these readings using the earthing strap as my negative and to me they look relatively strange values but I have to be honest and say I am not used to taking readings after a control module so I do not know how that influences the voltages.
Interestingly this motor appears to be the one that selects high or low ratio as when it is disconnected a warning appears on the dash 'range change not available' after reconnecting and doing a code clear on the transfer box control module the message disappears and range change works perfectly, as it did before disconnecting it, further reinforcing my suspicions that I am looking at the control module as the culprit.
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!
3rd Apr 2015 1:02 am
MGCarr
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
OK it has been a long time but I have made some progress on this and wanted to run the car for a week or two to make sure it really was a step forwarded. Gap gave me access to a firmware version for the IID tool that allowed me to re-flash the Transfer Case Control Module, I tried this along with recalibration but it made no difference, so I purchased a new TCCM from LR. As you will see from the picture below there are significant differences in the part numbers and version numbers, the top unit is the new one.
Apologies for the poor quality of the pic but hopefully you can see what I mean.
I used the IID tool to flash the new TCCM and to carry out the necessary calibrations and bingo I have a fault free TCCM, I can now get the special programs and the position indicator on the rotary dial remains illuminated.
Having allowed the car to go asleep I am now measuring a 30 ma current draw on the battery, slightly higher than LR quote but pretty close. I have now run the car for several weeks and this has all remained stable with just one remaining fault, that of the intermittent sport/command shift availability but I think I will start a new thread for that.
Thanks again to everyone for their help and encouragement.
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!
18th May 2015 8:53 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
It does seem a very long time since the TTCM suspicions first arose. Well done for sticking with it and fixing your issue.
Top work.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
Thanks Robbie, like you say it has been a long time but work and family commitments tend to get in the way. On the plus side the car has never been unavailable to use and the cost of the repairs has been relatively low compared to what others report on here, I hate the attitude of chucking components at a problem without some proper diagnosis.
The other benefit is that as a long time member of the Institute of Road Transport Engineers I consider ownership of a D3 and self maintainance as part of my continuous professional development
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!
19th May 2015 2:21 am
rsp
Member Since: 11 Jan 2006
Location: Goulburn, NSW
Posts: 161
Transfer Case ECU
Hi MGCarr, it looks as if I have a problem with the Transfer Case ECU that is causing battery drain, but no other faults reported on the IIDTool, or lights on the dash. I note that you reflashed a replacement ECU using your IIDTool, something I also have, but have not used it for that purpose as yet. If you can provide any further information as to exactly what you did, that would be appreciated. I would also be interested as to what you paid for the ECU. Many thanks.Disco 3 TDV6 HSE, Auto, White, Rear Diff Lock. ARB BB, Traxide DBS, GME TX3540S, Safari Snorkel, IIDTool-BT, Doran TPMS, Rijidij Spare Wheel Carrier, Two side by side Drifta drawers, cargo barrier and drop down fridge slide, ARB 47l Fridge, Yokohama A/Ts and out of date 17" Cooper STTs.
14th Oct 2016 11:54 am
rsp
Member Since: 11 Jan 2006
Location: Goulburn, NSW
Posts: 161
Use of IIDTool to flash TCCM ECU
No worries as I have worked out how to get the IIDTool to flash the TCCM ECU. If it is of interest, see my (separate) post on battery drain.Disco 3 TDV6 HSE, Auto, White, Rear Diff Lock. ARB BB, Traxide DBS, GME TX3540S, Safari Snorkel, IIDTool-BT, Doran TPMS, Rijidij Spare Wheel Carrier, Two side by side Drifta drawers, cargo barrier and drop down fridge slide, ARB 47l Fridge, Yokohama A/Ts and out of date 17" Cooper STTs.
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