Weird Goings on with 1.8's Alarm

ceedy · 28th June 2019, 09:15

my Sons reported his alarm keeps going off on the way home from work ?

But ts ok in the morning going there. seems a bit weird i thought so I took it to work myself about 15 miles compared to his 8 miles.

All ok on the way in , but coming home , after about 2 miles the alarm goes off . I pull in to a layby, switch motor off and key out , but nothing stops it. fob buttons , key in door bonnet/boot up and down .
Alarm was on for about 20 secs the goes off for a moment then alarm on again . did this for about 4 times then went off and I drove home all quiet. ??

this morning tried the car I got a single beep when fob pressed once to open driver door, then no beep on second press opens the others as expected.

Tried the same a bit later an on one click to unlock I got a quick chirp of the alarm.

If i cycle the locks on and off a number of time the alarm will go off and can be switched off by the fob button.

plenums all bone dry all the connectors i've check all all dry , done a battery reset .
Nothing reported on the dash.

Any clues peeps where to look or test .. ta

Chris

ceedy · 28th June 2019, 11:46

Had peer into the system with toaf. And loads of errors shown in the bcu, Ike and PDC sections.
Bonnet switch is mentioned twice

Yorkshire GOC · 28th June 2019, 16:54

The alarm/immobiliser ECU - on driver side A pillar can be damaged by water ingress - do you have a sun roof? - anyway can cause the alarm to play up. Might be worth dropping a PM to MarinaBrian or BigRuss.

ceedy · 28th June 2019, 18:44

No sunroof and the car is bone dry . no signs of water .

Did have a bit of water in the boot a long time back but all sorted for a while now .

Any wiring chafing I should look for ?

C

Yorkshire GOC · 29th June 2019, 11:09

Faulty bonnet switch can trigger random alarm events.

marinabrian · 29th June 2019, 21:11

All I can suggest is you clear the alarm log, then the newest entry will be the pinpoint of the cause.

It is certainly not a common problem, in fact I cannot recall seeing anything like this before

Brian

clf · 5th July 2019, 11:55

This was the inside of my non operational bbus prior to replacement. There were no previous tide marks in the plenum to suggest it was submerged at any point. Perhaps just corrosion inside it?

Sent from my SM-A600FN using Tapatalk

ceedy · 5th July 2019, 21:30

Touch various woody things ,

I'm hoping I've sorted it.

Did a 10 mile test today and no alarm sound,

ceedy · 8th July 2019, 08:29

I took out the sounder , seemed the simplest way to stop the noise

.

And being nosey took it apart to find this

,

Even tho' the unit has a rubber seal and was all dry inside..

the battery connector was goosed .. corroded pins and PCB.
the damp had wicked right up the Neg wire onto the battery.

So removed the whole connector cleaned it up and hard wired the battery direct to the PCB . plugged it back in, nearly blew my ears off

.
Switched off ok on the fob..

And the IPK's Diagnostic mode has returned

. wierd !

Will see over this week if its sorted ???

Chris

COLVERT · 8th July 2019, 11:26

Might not have been water damage. Just arcing from a poor connection could have caused that.-----

28th June 2019, 09:15	#1
ceedy This is my second home All Trophy Blue ,ZT260#50 , ZT CDTI Auto, ZR105+ and 1.8T Firefrost spoiling the Set . Join Date: Nov 2006 Location: Nr Sherborne But in Somerset.. Posts: 6,077 Thanks: 916 Thanked 1,214 Times in 768 Posts	Weird Goings on with 1.8's Alarm my Sons reported his alarm keeps going off on the way home from work ? But ts ok in the morning going there. seems a bit weird i thought so I took it to work myself about 15 miles compared to his 8 miles. All ok on the way in , but coming home , after about 2 miles the alarm goes off . I pull in to a layby, switch motor off and key out , but nothing stops it. fob buttons , key in door bonnet/boot up and down . Alarm was on for about 20 secs the goes off for a moment then alarm on again . did this for about 4 times then went off and I drove home all quiet. ?? this morning tried the car I got a single beep when fob pressed once to open driver door, then no beep on second press opens the others as expected. Tried the same a bit later an on one click to unlock I got a quick chirp of the alarm. If i cycle the locks on and off a number of time the alarm will go off and can be switched off by the fob button. plenums all bone dry all the connectors i've check all all dry , done a battery reset . Nothing reported on the dash. Any clues peeps where to look or test .. ta Chris __________________ The Three Bloo's Wifey's Zr105, MY CDTI & 260 #50 and Number One sons 1.8T in Firefrost When I were a lad Zero to 142 in 10.25 secs at the Pod on my Blown Norton. 210 Kart Champ in 70's Last edited by ceedy; 28th June 2019 at 15:06..

28th June 2019, 11:46	#2
ceedy This is my second home All Trophy Blue ,ZT260#50 , ZT CDTI Auto, ZR105+ and 1.8T Firefrost spoiling the Set . Join Date: Nov 2006 Location: Nr Sherborne But in Somerset.. Posts: 6,077 Thanks: 916 Thanked 1,214 Times in 768 Posts	Had peer into the system with toaf. And loads of errors shown in the bcu, Ike and PDC sections. Bonnet switch is mentioned twice __________________ The Three Bloo's Wifey's Zr105, MY CDTI & 260 #50 and Number One sons 1.8T in Firefrost When I were a lad Zero to 142 in 10.25 secs at the Pod on my Blown Norton. 210 Kart Champ in 70's

28th June 2019, 16:54	#3
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,069 Thanks: 1,842 Thanked 623 Times in 469 Posts	The alarm/immobiliser ECU - on driver side A pillar can be damaged by water ingress - do you have a sun roof? - anyway can cause the alarm to play up. Might be worth dropping a PM to MarinaBrian or BigRuss. __________________ She came off the Longbridge Line on 20-05-2003 The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.

28th June 2019, 18:44	#4
ceedy This is my second home All Trophy Blue ,ZT260#50 , ZT CDTI Auto, ZR105+ and 1.8T Firefrost spoiling the Set . Join Date: Nov 2006 Location: Nr Sherborne But in Somerset.. Posts: 6,077 Thanks: 916 Thanked 1,214 Times in 768 Posts	No sunroof and the car is bone dry . no signs of water . Did have a bit of water in the boot a long time back but all sorted for a while now . Any wiring chafing I should look for ? C __________________ The Three Bloo's Wifey's Zr105, MY CDTI & 260 #50 and Number One sons 1.8T in Firefrost When I were a lad Zero to 142 in 10.25 secs at the Pod on my Blown Norton. 210 Kart Champ in 70's Last edited by ceedy; 29th June 2019 at 15:11..

29th June 2019, 11:09	#5
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,069 Thanks: 1,842 Thanked 623 Times in 469 Posts	Faulty bonnet switch can trigger random alarm events. __________________ She came off the Longbridge Line on 20-05-2003 The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.

29th June 2019, 21:11	#6
marinabrian MG ZT Join Date: Jan 2011 Location: Newcastle Upon Tyne Posts: 20,151 Thanks: 3,565 Thanked 10,837 Times in 5,718 Posts	All I can suggest is you clear the alarm log, then the newest entry will be the pinpoint of the cause. It is certainly not a common problem, in fact I cannot recall seeing anything like this before Brian

5th July 2019, 11:55	#7
clf This is my second home MG ZT CDTi Join Date: Jan 2014 Location: carrick Posts: 7,859 Thanks: 3,494 Thanked 2,657 Times in 1,973 Posts	This was the inside of my non operational bbus prior to replacement. There were no previous tide marks in the plenum to suggest it was submerged at any point. Perhaps just corrosion inside it? Sent from my SM-A600FN using Tapatalk __________________ It is not gloss primer .............. it is duct tape silver!

5th July 2019, 21:30	#8
ceedy This is my second home All Trophy Blue ,ZT260#50 , ZT CDTI Auto, ZR105+ and 1.8T Firefrost spoiling the Set . Join Date: Nov 2006 Location: Nr Sherborne But in Somerset.. Posts: 6,077 Thanks: 916 Thanked 1,214 Times in 768 Posts	Touch various woody things , I'm hoping I've sorted it. Did a 10 mile test today and no alarm sound, __________________ The Three Bloo's Wifey's Zr105, MY CDTI & 260 #50 and Number One sons 1.8T in Firefrost When I were a lad Zero to 142 in 10.25 secs at the Pod on my Blown Norton. 210 Kart Champ in 70's Last edited by ceedy; 6th July 2019 at 07:21..

8th July 2019, 08:29	#9
ceedy This is my second home All Trophy Blue ,ZT260#50 , ZT CDTI Auto, ZR105+ and 1.8T Firefrost spoiling the Set . Join Date: Nov 2006 Location: Nr Sherborne But in Somerset.. Posts: 6,077 Thanks: 916 Thanked 1,214 Times in 768 Posts	I took out the sounder , seemed the simplest way to stop the noise . And being nosey took it apart to find this , Even tho' the unit has a rubber seal and was all dry inside.. the battery connector was goosed .. corroded pins and PCB. the damp had wicked right up the Neg wire onto the battery. So removed the whole connector cleaned it up and hard wired the battery direct to the PCB . plugged it back in, nearly blew my ears off . Switched off ok on the fob.. And the IPK's Diagnostic mode has returned . wierd ! Will see over this week if its sorted ??? Chris __________________ The Three Bloo's Wifey's Zr105, MY CDTI & 260 #50 and Number One sons 1.8T in Firefrost When I were a lad Zero to 142 in 10.25 secs at the Pod on my Blown Norton. 210 Kart Champ in 70's Last edited by ceedy; 8th July 2019 at 08:40..

8th July 2019, 11:26	#10
COLVERT This is my second home R75 Saloon. Join Date: Feb 2009 Location: France/or Devon. Posts: 14,003 Thanks: 3,851 Thanked 2,167 Times in 1,816 Posts	Might not have been water damage. Just arcing from a poor connection could have caused that.-----