Another 320 D thread...

shooter57

Hi lads I searched through the threads for this problem , I got a few answers but the questions asked wouldn't be the same as mine so I thought I'd post my own thread .

I got a 2003 320d bmw ,left it in for a service , garage said I need new front brake pads so I got them in , drove the car home and parked it up . The next morning when I start it up, the ABS , Traction control and handbrake warning lights are on , I brought it straight back to the garage who had a look and sent me to a different garage for a diagnostics to which I was left with a list of problems .

Also my radio screen is switching on and off the sound is still there but the display disappears and comes back .

Does anyone think this could be an electrical problem before I go to a BMW garage , it's to go in at the weekend but just wondering has anyone any experience of this , would it be something small I can fix myself befroe i go and pay big money :eek: .Thanks for any help .

dharn

radio and abs problems unlikely to be related ,abs traction control warning lights may relate to a well known abs module problem that bmw repair for small fee on newer cars, or it could be that the garage who fitted your pads left the abs sensors disconnected

AzureAuto

Theres no reason the ABS sensors should have been disconnected for a simple pad fitment. Is it possible they had to whack the wheels off the hubs to et at the brakes? In which case they may ahve broken one of the ABS sensors? Strange also that the lamps didn't illuminate immediately...All those lights would illuminate if there were a fault in the braking systems as they are al interlinked, (SRS, ESP, ABS etc.) A diagnostic plug in would be the way forward.

btkm8unsl0w5r4

I would think about the battery/alternator. BMW's go mad when the voltage is low and usually you get a bunch of errors from unrelated systems.

bazz26

When they changed the brake pads did they replace the brake pad wear sensors also? Or did they use non OEM BMW wear sensors? Not replacing the brake pad wear sensors or using non OEM BMW sensors can cause the ABS/TC and handbrake warning lights to light up the dashboard like a Christmas tree.

The other thing I would check is the condition of the battery, a battery on the way out could also cause electrical warnings.

shooter57

bazz26 wrote: »

When they changed the brake pads did they replace the brake pad wear sensors also? Or did they use non OEM BMW wear sensors? Not replacing the brake pad wear sensors or using non OEM BMW sensors can cause the ABS/TC and handbrake warning lights to light up the dashboard like a Christmas tree.

The other thing I would check is the condition of the battery, a battery on the way out could also cause electrical warnings.

Thanks for the replies . The sensors weren't changed , just the pads , he told me the sensors have to be ordered as a separate part , don't know myself why he didn't just order them as it looked to me like it needed new ones , he says the sensors were bridged ? I have a new battery out there I will try later.
Do you know this for a fact ? that has to be what happened here then ? it's too much of a coincidence otherwise.

bazz26

shooter57 wrote: »

Thanks for the replies . The sensors weren't changed , just the pads , he told me the sensors have to be ordered as a separate part , don't know myself why he didn't just order them as it looked to me like it needed new ones , he says the sensors were bridged ? I have a new battery out there I will try later.
Do you know this for a fact ? that has to be what happened here then ? it's too much of a coincidence otherwise.

The brake pad wear sensor works in conjunction with the pad so when your pads wear down to a certain level the sensor sends a warning to the dashboard telling you to get your pads changed. When the pads are changed the pad wear sensors also need to be changed at the same time. Also non OEM pad sensors can through out false warnings so make sure he orders OEM sensors.

shooter57

Thanks Bazz , funny thing is the brake light disc was never on , I just took mechanics word for it they needed changing ,I'm sorry now I didn't wait til the warning light came on to tell me !! It's beyond me how trained mechanics in garage don't know these things about brake sensors !!

shooter57

got the problem sorted if anyone's interested or if anyone is having the same problem , it turns out car needed a new wheel sensor , what I though could be a big expensive problem turned out to be very small ,my advice for anyone having their brake pads changed always make sure you get new brake pad sensors to go with them .

bazz26

shooter57 wrote: »

got the problem sorted if anyone's interested or if anyone is having the same problem , it turns out car needed a new wheel sensor , what I though could be a big expensive problem turned out to be very small ,my advice for anyone having their brake pads changed always make sure you get new wheel sensors to go with them .

When you say wheel sensor, do you mean the brake pad sensor?

btkm8unsl0w5r4

Thats what I was thinking....aren't pad sensors changed with the pads as standard as part of a pad service there only a few euro each? There is a wheel speed sensor to do with the tyre deflation warning system but how that would throw ABS problems is beyond me????

PaulKK

Correct me if I'm wrong lads but is surely there's no need to replace the sensor when it hasn't been triggered?

Its just if it makes contact with the disc when the pad is worn down that it should be replaced surely? They shouldn't be damaged or anything they are just slid into a small groove in the pad.

I know the sensors are only a tenner or something but I don't see the harm inn reusing the existing one if the warning light hadn't been triggered.

shooter57

As far as I know it was the brake pad sensor , I spoke to mechanic on the phone and he said ABS is fixed ! But it did get a new wheel sensor aswell ! he still has my car as you might see I posted in another thread the pulley came away in the engine so just waiting for that part now . Told him to change the breather filter aswell while he has it .

jayok

Duncan Obnoxious Nutshell wrote: »

... There is a wheel speed sensor to do with the tyre deflation warning system but how that would throw ABS problems is beyond me????

The speed sensors are used by ABS and the traction control system (or DSC / ASC or whatever) to determine the slip. These sensors are not related to the brake wear sensors.

It's possible that when changing the brake pads, the speed sensor was knocked, moved, broken, whatever. And this is possibly why the problem seemed related the the brake pad change.

Replacing the speed sensor (and resetting the ECU) would normally fix these.