9two8

Hi everyone,.. I,m a new member to this great site, and would be gratefull if someone could help with the following problem, on my 1980 928s.
The car has been owned by me for the past 16years, and I have just got her back on the road after it,s winter hibernation,......the problem I have is the BRAKE PAD warning is lit up on the dash,..

You can of course switch it off with the red switch, but that,s getting to be a pain, I had a similar problem last year and fixed it by cleaning the spade connectors that connect to the pads,... however tried that again with no luck.

Any help would be much appreciated.

Best wishes everyone
Ken
United Kingdom

Ron V

Sounds like you need a new brake pad sensor. There is one on each caliper and are available at 928 International. Good luck.

Mike Frye

Ken,

Silly question, but how are your pads?

9two8

Hi Mike,.. good point I know but yeah there fine,thanks

StratfordShark

If the pads are fine then you need to check the pad sensors (one in each wheel, inserted in the inner pad).

Mine's an S4 but assuming S has similar sensor arrangement:

- remove each tyre. Behind the wheel is a black plastic cylinder a couple of inches long mounted on bracket to steering knuckle which holds the pad and abs sensor connectors. The cylinder has a simple catch that you need to open (the catch may be out of site at back, so just peer round or feel for it - it opens easily with finger pressure).

- with catch opened you can pull out the pad sensor connector (to make sure it's not the abs sensor just follow the lead back from pad).

- the sensor has two 'female' connectors. Normally they are shorted out if the pad wear is OK, so to test just shove multimeter probes down the connector on ohms range and see if it's shorted. If it's open circuit then you've found your faulty sensor, and just need to pop it out the pad with needle nose pliers or screwdriver blade or similar. If it's short circuit as per normal then replace the connector and pop the catch back in.

- if after going round each wheel all the sensors are short circuit, then the problem is with the warning module/wiring between sensors and module.

Please post results of your tests on the individual sensors.

bd0nalds0n

This topic has gone round and round before. I think the wearing thru of a pad sensor--and the ultimate triggering of the brake pad warning light-- doesn't result from a short circuit, but rather an interrupted one. If any of your wiring is broken--or if you have any intermittant connections-- along any of the multiple stops around the car, it will trip the brake pad circuit light.

If what you're saying is correct, then if you unplugged all four brake pad sensors, the light would never come on, so long as all the other wiring was intact.

If you do a search for this phenomenon, a lot of us have had it, and it's a pain in the *** to track down if the problem doesn't exist at the brake pad sensor.

WallyP posted a great, detailed analysis of the entire brake pad sensor warning loop. Lots of potential failure points.

StratfordShark

If you unplug a sensor then wouldn't the light come on, since the circuit is no longer bridged by the sensor?

Was doing brakes recently and I'm sure that when I had a sensor out (I replaced them with new, though I got some out OK) the light would come on when I started the engine.

9two8

,.Thank,s guys for all help and suggestions, look,s like i,m going to have to remove each wheel in turn and check them out,..... will keep you posted,.. one thing I have,nt got to worry about is ABS

Brett928S2

Hi

Ummm....its possible NONE of the above will work....it didnt on mine...

I did ALL the above checks and my pad light is still on !!!!!!!!!

No idea why...I live with it...until I pull my pod then that pad bulb will be history!!!!!!!!

All the best Brett

928S2 AUTO V8 4.7 LTR 1986 IRIS METALLIC BLUE WITH X-PIPES, RMB, PROMAX CHIPS, KICKDOWN SWITCH, K&N,WIZARDS OF NOS - NITROUS KIT 150 HP - 505 BHP / 500 FT LBS TORQUE.
PCGB - 928 - FORUM - MODERATOR.
EMAIL : managingdirector@pchealthcare.co.uk

marton

try disconnecting the battery; that resets something somewhere
worked for me

Marton

Brett928S2

Hi Marton

Tried that as well...still no go lol

All the best Brett

Tom928

I found the sensor wire (the part leading to the warning unit) that is inside the engine compartment had the insulation burnt through due to being routed too close to the exhaust and the wire was hanging by just a couple threads. Some solder and shrink tubing with better routing fixed that annoyance.

bd0nalds0n

I went back and re-read your post and I think I misunderstood what you were trying to say. I didn't read 'test for a short circuit' as the same for 'test for continuity,' which is clearly what you were saying, so it was my fault--we are saying exactly the same thing and are in complete agreement.

marton

Hi Brett

about
"Tried that as well...still no go lol ..."

I know, I hope you are the exception that will prove the rule

Did you hit 200mph yet with your Nitro?

Cheers

marton

Brett928S2

Hi Marton

Nope but got a definite date to try a "STANDING MILE" vs some very serious competition.....

Link to event >> http://www.pistonheads.com/gassing/t...0&t=388939&i=0

List of competitors so far....

1. Longbow Cerb 4.2
2. BLUETHUNDER Cerb 4.2
3. Touching Cloth Cerb 4.2(if he can cancel his holiday)
4. Wilder Cerb 4.2
5. Byker28i Cerb 4.2+Camera
6. Steve T & Mrs T Cerb 4.5 + another camera
7. BCA and Jeff Cerbera 4.5 + data logger (needs to check holiday dates! )
8. Nelly1 Tuscan S (ish)
9. BossCerb Cerb 5.0
10. Cyclone1 Cerb 4.5 (Courtesy of Boss Cerb!)
11. Seasider Griff 500 (Reinstated!)
12. itsallyellow Cerbera Race car (if i'm aloud
14. Spartacus Cerb 4.2 + camera ( Make no. 14 on the list, not that I'm superstitious or anything!)
15. HarryW Cerbera 4.5ish
16. TooTall Paul Cerbera 5.0ish
17. hbeck Audi RS6
18. warpig1 Cerbera 4.0 (wey hey!)
19. boony 996tt
20. ThatPhilBrettGuy Ford GT
21: R1_jon 996 GT2
22.Petrolnog LP640 (If CUE99T goes in his 640, I may take the 599 if it arrives on time but outlook doubtful, 640 definate)
23. BLKROKT 996TT
24. Adrian w Noble M600 (ish)
24. N GTS Dodge Viper
25. 17ND F430 F1
26. Brummiewedge Cerb 6.3 LS1 Powered
27. Brett928S2 Porsche 928
28. Luckyp Ultima 550GTR
29. Venom500 Viper GTS
30. erik997 Carrera S
31. Grahamn Cerbera 4.5
32. Housemaster 996 MkII GT3
33. Hollowpockets T350t 3.6
34. dancaz mk1 tuscan factory red rose spec (decat and carbon cans ok???)
35. A GTS MG SV XPower
36. Markbe - SL600 bi turbo - date dep
37. MOD500 - 993 turbo - date dep
38. Nick ccc - Cerb Red Rose
39. Andysgriff - Cerb Red Rose
40. buzz01 - Cerb 4.5
41. CiderwithCerbie - Cerb 4.0 Speed Six
42. Mad Mark - 4.5 Cerbera
43. satman - Cerbie 4.5
44. ferrarispider F355
45. C8 CDS 4.5 cerbera/bournemouth
46. madbadger - Tamora
47. traxx - either Ferrari 430 coupe or Lamborghini Gallardo Spyder
48. ninja_eli - F430 Spider F1 - depending on date.
49. scottyboy - 993 TT
50. Bluesatin - 996tt X50 or Ultima GTR Slow!
51. speed_EM - Lamborghini Gallardo (confirming holiday dates)
52. Kippax - TVR Tuscan 4lt (decat & CC's)
53. Flea (ref Cyclone1) - Fiat Coupe 20VT (460bhp)
54. Olly - Cerbera 4.2
55. Deano - Cerbera RR 4.5
56. Frazer - 550 Maranello
57. Philo - 996 GT3 RS
59. James - Gallardo
58. Arash - Murci
59. olly - Cerb 4.2
60. toadusmodus - Cerb 4.2
61. cerbfan - Cerb 4.5
62. cerberowner - Cerb 4.2
63. R8nan - Cerb 4.2
64. DodgyDave (ref Cyclone1) - B5 RS4 (approx 700bhp)
65. Scareyspiders100 (ref Cyclone1) - B5 RS4 (standard)
66. DaveT (Ref Cyclone1) - B5 S4 (420bhp)


I am the only 928 allowed so far...so I better do well

I should have my new twin 28 lb system finished and running around 800 to 850 hp by then...

All the best Brett