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msb

Member Since: 28 Feb 2013
Location: Leeds
Posts: 78

Cruise control not working after installing auto box

A few months ago I had a manual 2004 Td5 with a NNN50020 ECU and functioning cruise control.

Due to the rust (

) in the ECU killing it on the way to Ashcroft's I now have an auto 2004 Td5 with a NNN50020 made from a NNNsomething else ECU by Gary at Alive and non functioning cruise control.

I'd like to get the cruise control working again, but appreciate having changed several things at once is not the best starting point.

Has anyone had to change anything after as auto conversion to keep the cruise control working?

The transfer box hasn't changed, so I don't think I need a speedo healer (and don't want to spend £80 if I don't have to) so I suspect it may be to do with the clutch switch, but work and the weather have prevented me from investigating too far as yet.

Does anyone have any more thoughts or suggestions?

Thanks

Mike

4th Jan 2018 8:38pm

grafty99

Member Since: 15 Aug 2012
Location: North Devon
Posts: 4790

I think the clutch switch is push to break so the two wires need to be joined for the ecu to think the clutch isn't pressed

The cruise control doesn't work on a manual if you unplug the switch

2002 90 Td5 Station Wagon
1990 Vogue SE
Triumph Tiger Explorer 1200
Td5 90 Thread http://www.defender2.net/forum/topic50767.html
Tdi 110 Thread https://www.defender2.net/forum/topic69562.html
RRC Thread http://www.defender2.net/forum/topic54492.html
Instagram http://www.instagram.com/george_grafton

4th Jan 2018 8:45pm

msb

Member Since: 28 Feb 2013
Location: Leeds
Posts: 78

Thanks grafty, that's pretty much where I'd got to (but couldn't remember if the circuit was normally open or closed).

If I just make sure there's 12v at pin 35 I should be right then, shouldn't I?

Thanks

Mike

4th Jan 2018 8:50pm

grafty99

Member Since: 15 Aug 2012
Location: North Devon
Posts: 4790

Yes it should do the trick. Unless you bridge the connection under the bonnet? 2002 90 Td5 Station Wagon
1990 Vogue SE
Triumph Tiger Explorer 1200
Td5 90 Thread http://www.defender2.net/forum/topic50767.html
Tdi 110 Thread https://www.defender2.net/forum/topic69562.html
RRC Thread http://www.defender2.net/forum/topic54492.html
Instagram http://www.instagram.com/george_grafton

4th Jan 2018 9:06pm

msb

Member Since: 28 Feb 2013
Location: Leeds
Posts: 78

As I didn't do the conversion (Ashcroft's did) I'm not sure what happened to that circuit, and Dave (surprisingly) wasn't offering any help...

I'll try pin 35 and see what happens. I'm guessing I can tap off a supply voltage on a nearby pin.

4th Jan 2018 9:15pm

grafty99

Member Since: 15 Aug 2012
Location: North Devon
Posts: 4790

Yeah that would do, if the wiring isn't obvious under the bonnet then an under seat connection would be easier

4th Jan 2018 9:27pm

msb

Member Since: 28 Feb 2013
Location: Leeds
Posts: 78

I'll have another look under the bonnet if it is ever light enough and dry enough when I'm at home as compleing the circuit there (if it is there) would probably be easier, but if the clutch circuit is open wouldn't that reduce overall power?

I thought that circuit dropped the throttle output, or limited revs, or something to promote smoother gear changes. That was the reason I did have a separate switch in it previously to keep it closed when trialling or competing....

Back to being confused again now...

4th Jan 2018 9:40pm

grafty99

Member Since: 15 Aug 2012
Location: North Devon
Posts: 4790

It rev hangs and generally softens throttle response. Probably not noticeable on an auto though.... 2002 90 Td5 Station Wagon
1990 Vogue SE
Triumph Tiger Explorer 1200
Td5 90 Thread http://www.defender2.net/forum/topic50767.html
Tdi 110 Thread https://www.defender2.net/forum/topic69562.html
RRC Thread http://www.defender2.net/forum/topic54492.html
Instagram http://www.instagram.com/george_grafton

4th Jan 2018 9:44pm

msb

Member Since: 28 Feb 2013
Location: Leeds
Posts: 78

That makes sense I guess.

I'll give it a whirl tomorrow or Saturday.

Thanks for your help.

4th Jan 2018 9:49pm

grafty99

Member Since: 15 Aug 2012
Location: North Devon
Posts: 4790

No worries

4th Jan 2018 9:59pm

MadTom

Member Since: 10 Sep 2013
Location: Olomouc
Posts: 635

There are some small differences in TD5 ECU for manual. Auto ECU has CAN driver for communication with Disco2 auto ECU, and is missing circuit (some resistors) for clutch pedal sensing. I ha modified some auto ECUs to use in manual - replacing the whole software (not just remap) and adding those missing resistors. The rest is the same.
Corrosion inside ECU is not unknown - normally after drowning, but it can be also because of humidity in car. ECU internal are covered with some conformal coating (looks like a silicon) to protect them from moisture, but it is not 100%. "Drobek" = The Small One - Discovery 2, "Blufínek" = The Blue Thing - Defender 130, and for me at least Ford Mondeo

5th Jan 2018 7:59am

grafty99

Member Since: 15 Aug 2012
Location: North Devon
Posts: 4790

I doubt that they would have changed the ECU when converting to auto, especially as there are no defender auto specific maps. Also if the vehicle was previously tuned then they would loose the tune which I'm sure wouldn't impress the customer! 2002 90 Td5 Station Wagon
1990 Vogue SE
Triumph Tiger Explorer 1200
Td5 90 Thread http://www.defender2.net/forum/topic50767.html
Tdi 110 Thread https://www.defender2.net/forum/topic69562.html
RRC Thread http://www.defender2.net/forum/topic54492.html
Instagram http://www.instagram.com/george_grafton

5th Jan 2018 8:37am

AJC

Member Since: 30 Nov 2015
Location: Lancashire
Posts: 1364

Grafty, have you got cruise on your TD5?

5th Jan 2018 8:59am

grafty99

Member Since: 15 Aug 2012
Location: North Devon
Posts: 4790

I do yes

5th Jan 2018 9:13am

MadTom

Member Since: 10 Sep 2013
Location: Olomouc
Posts: 635

I agree with the change of ECU. There is a bigger problem with the change of gearing - manual gearbox has different gearing from auto gearbox. So the speedo healer may not be enough to overcome this.
Engine ECU has some ratio ranges limits between RPM and vehicle speed, more than one, because cruise control works not only in fifth gear. And with auto gearbox this Is totally different. When the auto gearbox is locked, than the ratio is fixed, but when not, than the ratio changes, as the car speed is rising and the torque convertor is slipping. "Drobek" = The Small One - Discovery 2, "Blufínek" = The Blue Thing - Defender 130, and for me at least Ford Mondeo

5th Jan 2018 9:50am

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