Brake Pad Warning Light
- Thread starter sr.944man
- Start date
chrisg
Member
Sounds to me like 1. Sensor issue (consider fitting new ones) 2. Wiring to/from sensor (or the plugs needs cleaning)- if your car has ABS the brake pad sensor wires/plugs are on the same wiring loom - different shape plugs though.
Does your car have ABS and if so does it work ? - Sometimes the short brown earth wire out of the ABS/Brake pad sensor block breaks off where it connects to the body.
Yes you're right it is a MOT failure.... BUT.... I've not had sensors fitted on my Turbo for > 10yrs ( just blocked off the white connector blocks with snipped of connectors) - I sit in the car to do all the MOT testing with our local garage and it always passes....
Does your car have ABS and if so does it work ? - Sometimes the short brown earth wire out of the ABS/Brake pad sensor block breaks off where it connects to the body.
Yes you're right it is a MOT failure.... BUT.... I've not had sensors fitted on my Turbo for > 10yrs ( just blocked off the white connector blocks with snipped of connectors) - I sit in the car to do all the MOT testing with our local garage and it always passes....
scam75
Well-known member
Assuming your warning lights and brake pad sensors are working ok, the only thing that illuminates the pad warning light is a sensor going open circuit, so basically when the pad wears down sufficiently the pad sensor breaks the circuit, and the light comes on. This should never be intermittent as it's like being pregnant, you either are or you aren't!!
If you take an old sensor (or 4) and cut the wires down and twine them together, and plug them in, your brake pad light will never light up. I think you may have a wiring fault somewhere or a bad earth.
Stuart
If you take an old sensor (or 4) and cut the wires down and twine them together, and plug them in, your brake pad light will never light up. I think you may have a wiring fault somewhere or a bad earth.
Stuart
jonnyporsche
PCGB Member
Has anyone please got a simple answer to this please. The brake pads warning light goes out when the engine is fired up but comes back on when the car moves, near new pads are fitted as can be seen, and is this an MOT fail just because the warning light comes on.
Waylander
Active member
The brake pad sensors are pretty simple,
the sensor in the pad is a wire loop, with the circuit complete on all four the light will stay off, when the sensor wears the loop touches the disk and this provides a ground to the loop circuit and puts the light on
the warning definitely says brake pad warning, and goes on and off, not just the big red !
if your car has ABS I would suggest a mis-plugged sensor
the sensor in the pad is a wire loop, with the circuit complete on all four the light will stay off, when the sensor wears the loop touches the disk and this provides a ground to the loop circuit and puts the light on
the warning definitely says brake pad warning, and goes on and off, not just the big red !
if your car has ABS I would suggest a mis-plugged sensor
jonnyporsche
PCGB Member
Thanks guys for all your inputs. The rear pads don’t have sensors on I have checked the earths and connectors but not the loops in the pads I’ll start with that and take it from there, thanks again.
chrisg
Member
jonnyporsche said:
Assuming the Pad sensor system is the same on a 1987 Turbo as a 1988 (perhaps someone more knowledgeble than I can confirm ?) - this could be where your problem lies: you should have 4 x sensors plugged in one on each wheel.
On the '88 Turbo the front pads have bilateral wear sensors, single wear sensor on the rear it's a single sensor. The sensors plug into the white/pale yellow connector blocks - different shaped plug to the ABS sensors (round profile vs square ) - so unlikely they've been mixed up.
If all else fails, suggest you go for the 'fix' with wires stripped and connected to fool the system into thinking there's no wear. IMHO, as someone who does less than 5K PA and constantly tinkering/monitoring the car wear sensors are overkill
jonnyporsche
PCGB Member
Will have another look this weekend, thanks.chrisg said:jonnyporsche said:
Assuming the Pad sensor system is the same on a 1987 Turbo as a 1988 (perhaps someone more knowledgeble than I can confirm ?) - this could be where your problem lies: you should have 4 x sensors plugged in one on each wheel.
On the '88 Turbo the front pads have bilateral wear sensors, single wear sensor on the rear it's a single sensor. The sensors plug into the white/pale yellow connector blocks - different shaped plug to the ABS sensors (round profile vs square ) - so unlikely they've been mixed up.
If all else fails, suggest you go for the 'fix' with wires stripped and connected to fool the system into thinking there's no wear. IMHO, as someone who does less than 5K PA and constantly tinkering/monitoring the car wear sensors are overkill
jonnyporsche
PCGB Member
Problem sorted, thanks for all your suggestions, using a multimeter and patience I’ve traced the fault to a section of loom, with a bit of modification the warning light now goes out, bingo 
Posts made and opinions expressed are those of the individual forum members
Use of the Forum is subject to the Terms and Conditions
