Air Bag warning light/Brake fault light

mickywillis · 16th November 2007, 21:29

Ladies and Gents, I have what has become a rather annoying (irritating more than anything) problem which has manifested itself on my 52 plate CDT Tourer.
About 5 weeks ago, the airbag warning light came up on the dash. thought nothing of it (just another R75 software glitch I thought), carried on my merry way, parked and did whatever I was doing. Came back to car, started it as usual and no warning light.
This has progressively got worse over the last few weeks. On the 1st start of the day (usually in the evenings), the airbag light comes on and stays on until I switch the ignition off and it doesn't reappear for a further 2 or 3 starts, then comes back on. Now coupled with this light coming on, the brake failure warning light will come on every so often, as soon as I turn ignition on and off again to extinquish the airbag lamp. I fitted all new pads, discs and sensors about 2 months ago, brake fluid is OK and no obvious defects with braking system (keeps pedal pressure, ABS light behaves OK, ABS works fine, no leaks)
The general sequence I use is: start car, airbag light comes on, turn ignition off and restart, airbag light goes out and then brake failure warning light illuminates and goes out. All is well for a couple of stop/starts and then same thing occurs. I've even tried being outside the car when starting 1st time, to make ECU think no one sitting in seat, hey I'll turn the airbags off, but still no joy.
i guess the next course of action is to start looking at the seat switches and connectors (although I have pushed them all back together firmly), seat belt tensioners and all other airbag associated connections.

Anyone got any suggestions? are the 2 warning lights indicating anything major suspicious or is it just coincidence they come on one after each other? If there was a problem with the brake system, would the warning stay illuminated in the information display or is it designed to warn on 1st start up and then extinguish until the next start up??
thanks,

mattthetourer · 16th November 2007, 21:44

Air bag warning light seems a common problem.The sensor wiring is under both seats.Try a search on the site and you will get tips on a fix.Some resort to a zip tie around the switch.

JohnDotCom · 16th November 2007, 21:49

Quote:

Originally Posted by mattthetourer

Air bag warning light seems a common problem.The sensor wiring is under both seats.Try a search on the site and you will get tips on a fix.Some resort to a zip tie around the switch.

I think he might mean Tie around the Plug Connector?

But of course I may be Wrong, Often am.

Or Cut and solder for permanent repair.

T-Cut · 16th November 2007, 23:25

Quote:

Originally Posted by mickywillis

Anyone got any suggestions? are the 2 warning lights indicating anything major suspicious or is it just coincidence they come on one after each other?

There's no operational connection between the two. They are separate systems, but may possibly be affected by a fault in the ECU for example. Have you confirmed the plenum is dry?

Quote:

If there was a problem with the brake system, would the warning stay illuminated in the information display or is it designed to warn on 1st start up and then extinguish until the next start up?

The brake pad wear indicator normally stays on once the sensor goes open circuit. It doesn't normally go on and off in the way you describe. This is why I wonder about another cause.

Note also that whenever the air bag warning is on (for whatever reason) the car's safety systems (air bags and seat belt pretensioners) are disabled.

TC

Jules · 17th November 2007, 01:02

I too feel the faults you have are unrelated.
Snip out the yellow connectors under the seats (ones with the black cabling as apposed to the yellow cable feeding the pre tensioners, which to date don't seem to give trouble)

Use good quality plug and socket connectors instead. The official Rover modification is around £100 for a bit of wire and some modified plugs, crazy price for what they are.

The reason for the Rover plugs failing is because the male pins in the yellow housing are gold plated and the female sockets are nickel plated..............
resulting in dissimilar metals reacting together called the cathodic effect. (giving a resistive bad connection)

Silly design that costs pence to fix but hey, don't knock Rover for this, the same problem happens to Renault Clio's and some Vauxhalls.

Aga · 15th December 2007, 11:59

Took mine to the local independent about a year ago and he seemed to fix it. However, it is now back (as usual, only intermittently)
I have discussed it again with him and he stated that the only real solution would be to disable the particular air bag (he stated it is usually the one in the A Pillar) so that all the otheres remain OK, but you will have to do without the protection from that particular one!

Can this be true? Or is he mistaken?

T-Cut · 15th December 2007, 15:11

Quote:

Originally Posted by Aga

I have discussed it again with him and he stated that the only real solution would be to disable the particular air bag - - - - Can this be true? Or is he mistaken?

It's not true. Is he mistaken? Yes. That's a silly idea.

The fault is very common and tends to recurr unless the faulty connection is fixed permanently, such as by soldering the wires together or fitting a better quality connector. It may simply require retightening. It's possible that a different connector has failed. There are two under each front seat.

There's lots of info on this. A quick word search for 'air bag warning' will keep you busy for an hour or two.

TC

Johnb · 22nd January 2008, 16:32

Like most 75 owners I too had the problem! Remove front seats - or at least undo fixing bolts and tilt seat up. Cut the connectors off and replace with a normal electrial connector (available at Halfords for a few pence). Refit and the problem will go! A tip is - only cut one wire at a time so that you do not cross he wires when re-connecting!

Jon Linley · 30th June 2010, 22:07

Regarding cutting out the yellow connectors and refitting with a new connector is it just a case of joining the wires together.
On the drivers side there are two blue wires that join to a red/orange wire and a red/purple wire
On the passenger side there are two blue wires that join to a white/orange wire and a white/purple wire
I have cut mine out and joined them together but the light is still on , the old fix of unconnecting and re connecting the yellow plugs did work at first but I thought I would try a more permanent fix. However I now feel like banging my head on the wall.
Could it be the other plug under the seat or am I doing something wrong

Somebody somewhere please help !!!

justmicky · 1st July 2010, 06:50

My experience:

http://www.the75andztclub.co.uk/foru...g+warning+sign

http://www.the75andztclub.co.uk/foru...ht+staying+lit

http://www.the75andztclub.co.uk/foru...g+light+update
__________________
jm

16th November 2007, 21:29	#1
mickywillis Avid contributor Rover 75 Tourer CDT Connosieur Auto Gone but not forgotten!!Now have a Jag X Type Diesel Estate,:) Join Date: Mar 2007 Location: worcester park Posts: 145 Thanks: 0 Thanked 4 Times in 2 Posts	Air Bag warning light/Brake fault light Ladies and Gents, I have what has become a rather annoying (irritating more than anything) problem which has manifested itself on my 52 plate CDT Tourer. About 5 weeks ago, the airbag warning light came up on the dash. thought nothing of it (just another R75 software glitch I thought), carried on my merry way, parked and did whatever I was doing. Came back to car, started it as usual and no warning light. This has progressively got worse over the last few weeks. On the 1st start of the day (usually in the evenings), the airbag light comes on and stays on until I switch the ignition off and it doesn't reappear for a further 2 or 3 starts, then comes back on. Now coupled with this light coming on, the brake failure warning light will come on every so often, as soon as I turn ignition on and off again to extinquish the airbag lamp. I fitted all new pads, discs and sensors about 2 months ago, brake fluid is OK and no obvious defects with braking system (keeps pedal pressure, ABS light behaves OK, ABS works fine, no leaks) The general sequence I use is: start car, airbag light comes on, turn ignition off and restart, airbag light goes out and then brake failure warning light illuminates and goes out. All is well for a couple of stop/starts and then same thing occurs. I've even tried being outside the car when starting 1st time, to make ECU think no one sitting in seat, hey I'll turn the airbags off, but still no joy. i guess the next course of action is to start looking at the seat switches and connectors (although I have pushed them all back together firmly), seat belt tensioners and all other airbag associated connections. Anyone got any suggestions? are the 2 warning lights indicating anything major suspicious or is it just coincidence they come on one after each other? If there was a problem with the brake system, would the warning stay illuminated in the information display or is it designed to warn on 1st start up and then extinguish until the next start up?? thanks, Last edited by mickywillis; 16th November 2007 at 21:32..

17th November 2007, 01:02	#5
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	I too feel the faults you have are unrelated. Snip out the yellow connectors under the seats (ones with the black cabling as apposed to the yellow cable feeding the pre tensioners, which to date don't seem to give trouble) Use good quality plug and socket connectors instead. The official Rover modification is around £100 for a bit of wire and some modified plugs, crazy price for what they are. The reason for the Rover plugs failing is because the male pins in the yellow housing are gold plated and the female sockets are nickel plated.............. resulting in dissimilar metals reacting together called the cathodic effect. (giving a resistive bad connection) Silly design that costs pence to fix but hey, don't knock Rover for this, the same problem happens to Renault Clio's and some Vauxhalls. __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block Last edited by Jules; 17th November 2007 at 01:05..

22nd January 2008, 16:32	#8
Johnb Newbie Rover 75 Connoisseur Join Date: Aug 2007 Location: Hampshire Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts	Johnb Like most 75 owners I too had the problem! Remove front seats - or at least undo fixing bolts and tilt seat up. Cut the connectors off and replace with a normal electrial connector (available at Halfords for a few pence). Refit and the problem will go! A tip is - only cut one wire at a time so that you do not cross he wires when re-connecting!

30th June 2010, 22:07	#9
Jon Linley Newbie MG ZT Join Date: Sep 2009 Location: Farnsfield Notts Posts: 9 Thanks: 0 Thanked 0 Times in 0 Posts	Air bag warning light Regarding cutting out the yellow connectors and refitting with a new connector is it just a case of joining the wires together. On the drivers side there are two blue wires that join to a red/orange wire and a red/purple wire On the passenger side there are two blue wires that join to a white/orange wire and a white/purple wire I have cut mine out and joined them together but the light is still on , the old fix of unconnecting and re connecting the yellow plugs did work at first but I thought I would try a more permanent fix. However I now feel like banging my head on the wall. Could it be the other plug under the seat or am I doing something wrong Somebody somewhere please help !!!

16th November 2007, 21:44	#2
mattthetourer Regular poster mg zt t Join Date: Aug 2007 Location: peterborough Posts: 49 Thanks: 0 Thanked 0 Times in 0 Posts	Air bag warning light seems a common problem.The sensor wiring is under both seats.Try a search on the site and you will get tips on a fix.Some resort to a zip tie around the switch.

15th December 2007, 11:59	#6
Aga Gets stuck in MG ZT+ CDTi Black Pearl Join Date: Dec 2006 Location: Portchester (nr Portsmouth) Posts: 534 Thanks: 10 Thanked 0 Times in 0 Posts	Took mine to the local independent about a year ago and he seemed to fix it. However, it is now back (as usual, only intermittently) I have discussed it again with him and he stated that the only real solution would be to disable the particular air bag (he stated it is usually the one in the A Pillar) so that all the otheres remain OK, but you will have to do without the protection from that particular one! Can this be true? Or is he mistaken?

1st July 2010, 06:50	#10
justmicky I really should get out more....... Rover 75 Saloon 1.8 Club SE Join Date: May 2008 Location: north west Posts: 2,160 Thanks: 0 Thanked 1 Time in 1 Post	My experience: http://www.the75andztclub.co.uk/foru...g+warning+sign http://www.the75andztclub.co.uk/foru...ht+staying+lit http://www.the75andztclub.co.uk/foru...g+light+update __________________ jm