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mattlt

Member Since: 28 Nov 2023
Location: Corsavy
Posts: 11

2011 Defender 110 Puma 2.4 SW Orkney Grey

won't start and no horn, completely stumped!

Hi all

I have a 2011 puma (2.4)

The horn wasn't working. Needed to get it working for it's controle technique (I'm in France, MOT).
Checked fuses, all fine...

Drove it up to the workshop.

Checked both horn units behind the lights. They seem fine and indeed it I tried set the alarm with one of the doors open the horn would beep twice (as it should do I believe).

Took off the plastic casing around steering wheel to get access to stalks and connectors.
Found that horn switch seemed to be broken, didn't click properly. I had already replaced it once before when it (indicators) broke, so ordered a new one.

Put everything back together so could drive it while waiting for the new horn control.

Wouldn't start, or even turn over!

Very strange indeed!

New stalk switch unit arrived, installed this. No change, no horn and no starter motor action!

While messing around with the ignition and controls I had twice accidentally turned the starter briefly.

Checked the started solenoid/starter with a wire direct from battery. Turns over fine.

Checked 12V from back of ignition (White/red) and to the starter relay in the under seat fuse box. There is 12V at the relay no problem and can hear the relay operating when I turn the key. However it would not turn the starter motor. Checked relay, swapped with others and still the same.

Checked the negative/ground side of the relay socket and found it had a connection but a very high resistance. I ran a cable direct from the relay socket to the battery negative and then turning the key in the ignition turns the starter fine, but the engine still won't run.

So is this then an immobilizer problem? Plugged in the Gap IId with latest firmware but this doesn't find anything....

Tried both keys/fobs, makes no difference.

Checked ALL fuses, no problems.
When turning the key in the ignition all dash lights operate as normal, I read online people asking if the temp gauge goes to max but mine doesn't.

So in summary:
- Still have the horn that doesn't work, even with a new control.
- Now it won't turn over either unless I run a wire from the negative control terminal on the starter relay socket to the battery negative.
- Even when I do that the engine won't run.
- Gap IId doesn't show any errors.

I still have the first problem but now have a completely immobilized truck! I must have created the not starting problem by messing around with the horn switch because it was starting fine before, but I have no idea what it is!

Any pointers GREATLY appreciated!

28th Nov 2023 5:18pm

Stacey007

Member Since: 25 Sep 2015
Location: Cheshire
Posts: 3748

Hello

I had a different problem where mine cut out randomly...

However like you No codes, nothing to go on.

Quick change was the starter relay as cheapest quick fix if that.... it wasn't on my case,

Next swap was the ignition switch, change that and its been working perfectly since.

I guess as its not turning its not logging any codes as its not getting any info past the ECU? It maybe you have upset something while messing with the horn?

This was my long post....
https://www.defender2.net/forum/topic56773.html

Good luck

29th Nov 2023 9:11am

MK

Member Since: 28 Aug 2008
Location: Santiago
Posts: 2414

2007 Defender 110 Puma 2.4 SW Chawton White

I had such issue but on a 2.2 due to an immobilizer problem.
I guess if you bypass the starter relay it will have the same effect than running the wire from (-) to the starter. Puma 110" SW

.............................................................
Earth first. Other planets later

29th Nov 2023 10:13am

mattlt

Member Since: 28 Nov 2023
Location: Corsavy
Posts: 11

Hi,

Thanks so much for both taking the time to share your experiences.

I swapped the starter relay for another so pretty confident it's not that.

However, the ignition barrel is a surefire suspect! It has been sticking when turning the key for a long time. I have ordered one this evening. Not quite sure why playing around with the horn stick would cause it to finally give up but who knows.

Don't think it explains the horn either, but you never know. I don't like the electrics on the puma, does strange things!

I'll post any updates for others.

Thanks again.

29th Nov 2023 7:53pm

MK

Member Since: 28 Aug 2008
Location: Santiago
Posts: 2414

"I don't like the electrics on the puma, does strange things!"

Absolutely

By the way, terminals on the ignition switch are very fragile! Puma 110" SW

.............................................................
Earth first. Other planets later

29th Nov 2023 8:00pm

mattlt

Member Since: 28 Nov 2023
Location: Corsavy
Posts: 11

Thanks MK

Well maybe I finally broke a terminal in messing around.

I've already had fun with the electronics. When the back window broke and I replaced it I swapped the stop light for a LED version.... Then found that often when pushing the accelerator there was a delay in the engine accelerating.. I didn't think this could be linked but my local garage said put the old light back. I did and the problem went away!

29th Nov 2023 8:07pm

Stacey007

Member Since: 25 Sep 2015
Location: Cheshire
Posts: 3748

Hello

Hopefully the ignition barrel sorts the starting issue, The horn issue can wait for another day if that's the case, Or wire in a set of air horns off a separate switch

30th Nov 2023 3:58pm

mattlt

Member Since: 28 Nov 2023
Location: Corsavy
Posts: 11

Hi all

Update, and not a good one!

So installed a new ignition barrel, so now that is new as well as the hot/indicator/high beam flash stalk...

No physical change, when I turn the key I hear the starter relay click but the starter does not turn, nor does the horn work.

However, the alarm/indicator light on the dash no longer flashes as it did before and I have an error on the IId:

P1602-31
Immobilizer/engine control module communication error - Frequency modulation/pulse with modulation failure - no signal (6

So it becomes stranger and stranger!

5th Dec 2023 9:21am

Stacey007

Member Since: 25 Sep 2015
Location: Cheshire
Posts: 3748

oooh I was hoping you would have had a result....

I'm just guessing now.... but I would discounted the battery for 30 seconds reconnect and hope.

I assume the car battery is fully charged.

Hopefully others can help

5th Dec 2023 9:52am

MK

Member Since: 28 Aug 2008
Location: Santiago
Posts: 2414

From other forum:

Bassically with a Nanocom (or similar I guess) uncheck all settings from group I of the AS10. Save the changes. This should turn the immo off and if everything elase is ok, the engine should start. AT YOUR OWN RISK.

http://www.landroverclub.com.ar/viewtopic.php?f=261&t=152125 Puma 110" SW

.............................................................
Earth first. Other planets later

5th Dec 2023 10:17am

AndyS

Member Since: 18 Aug 2012
Location: London
Posts: 595

2011 Defender 110 Puma 2.4 XS CSW Sumatra Black

Have you checked the mega fuse? The starter is fed directly from the battery and there's a huge 500A fuse that lives behind a red plastic cover on the positive line coming off the battery inside the battery box. The service manual says to replace the cable and mega fuse as one unit but there's no need, you can just replace the fuse if it's blown. Check it with a multimeter, my one blew and it took me ages to discover it, another quirk of the late Defenders!

There it is, bottom right in the picture...

Click image to enlarge

6th Dec 2023 6:48pm

Ianh

Member Since: 17 Sep 2018
Location: Essex
Posts: 1997

Check fuse 6 and fuse 7 in the underseat fuse box, these serve the 10AS alarm unit. You may have blown one in changing over the ignition switch.

If it was a fuse and things go back to the way they were, i.e alarm lights on dash work, now try to start.

Also is the transponder coil around the top of the ignition barrel in place and connected. This works with the fob as part of the immobiliser.

Have you resynchronised the fob with the 10AS, with doors shut press fob lock button 4 times in quick succession, then the unlock button once.

If still not starting It could be the instrument cluster (IPAC) , you can try the instrument cluster shunt, you remove the IPAC, remove the wiring connector to it, leave it unconnected and bridge pins 3 and 4 with a paper clip or equivalent size solid wire, and with the IPAC still disconnected and connector pins 3 and 4 bridged with a wire try and start the engine as normal.

See page 7 of this topic near bottom, post from Martin. https://www.defender2.net/forum/topic47486...p;start=90

This is the connector on the IPAC

Click image to enlarge

To release it Push down on tab (green arrow). This releases the latch which you swing across (orange arrow).

Click image to enlarge

I obtained these pics from posts by Martin (site admin and owner) and Redline ( member) , thanks to them for posting.

Also worth checking the 30Amp fuse in the seatbox, this is not shown on the LR circuit diagrams but read this short topic ,posts from Martin at bottom, and you will see it’s role ( feeds starter relay) , location and updated diagrams https://www.defender2.net/forum/topic78128.html?highlight=fuse

6th Dec 2023 8:51pm

Ianh

Member Since: 17 Sep 2018
Location: Essex
Posts: 1997

Hi Mattlt, did you resolve your issue ?

13th Dec 2023 6:09pm

mattlt

Member Since: 28 Nov 2023
Location: Corsavy
Posts: 11

Hi all.
An update.

I checked every single fuse and there was nothing blown. I didn't try the IPAC shunt however...

I gave up trying to fix it and got my mechanic to come and pick it up. However, he couldn't find what it was so we finally decided to take it to a main dealer.

They have come back and said it's (almost) certainly the AS10 unit. I was hoping for a certainly but it seems not.

They say that as these are no longer made, their suggestion is to update it all to the siemens unit found on the later 2.2 models... However this involves changing the IPAC as well as far as I understand it... So this route would presumably fix it but seems a bit drastic!

I've read a few posts about replacing the AS10 with a 3rd party unit, for example the Mobi4 from Labtonx.com.au. This would seem a cheaper and more reliable solution to me. I've sent them an email but not heard back yet.

Does anyone have any views on this?

Thanks all!

5th Feb 2024 4:41pm

Ianh

Member Since: 17 Sep 2018
Location: Essex
Posts: 1997

I would do the ipac shunt first, it does not take long. It really does seem that the 10AS immobilisation signal is not getting to the engine ECU, and on the 2.4 it goes via a connection within the IPAC. By shunting that on the connector you are proving it’s not the Known IPAC issue.

If it’s not that then it could be wiring from 10AS to IPAC or IPAC to engine ECU. Which you can tap out with a multi meter.

If not that you can get your 10AS checked , and if needs be, fixed by technozen https://www.technozen-electronics.co.uk/la...-services/ worth giving them a call or email as another member had trouble getting a response recently.

5th Feb 2024 5:04pm

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