E36 Brake Pedal Travel Sensor Faulty With New Speakers

gtf28

New member
Hi
E36 M43 12/1996
So my brakes are 100%, I replaced rear speakers( just swopped them out with 4" audison speakers), Drove off and while braking I noticed the brake pedal went in further at low speed than usual then a weird knocking noise came from the pedal and the pedal seems to be trying to push outward(only at low speed), brake pads are barely 3 months old, disks are just under a year old and no ABS warning light on dash. So its doing this weird knocking sound and trying force the pedal out with no effect on braking force(braking force is normal). Guy told me brake pedal travel sensor (he drove it and he is a mech), replaced it and still there, so a month later I disconnected the right speaker ( cant remember why) and boom it works 100% no knocking pedal takes less force to brake at low speed and feels stiffer, so im driving with a disconnected speaker, been to 2 auto-electricians, 1 says control module needs replacing(did not make sense to me) other one says go to BMW, phoned bmw Paarl, E36 is too old non of them has worked on 1, I must wait for the manager. So any ideas at all?
My speaker boxes does say ABS on them, but like I said new speakers are fitted in the box and top connector is plugged in (no change at all to connectors or wires cut/spliced). Put the old rotten speaker back into the car on the right side and still knocking and pedal goes in further at low speed. Diconnect only the right speaker and boom works fine. Please help.

*Update* pulled my headunit (maybe wires touching there) and put orginal BMW Business RDS in activated with my code and connected speaker did not resolve the issue although alot of other things started working like the ignition ding noise and other noises the car makes, unplugged speaker and then worked so headunit and wirering is not the problem since oem headunit has connector. Put all the oem speakers back and still no change.
 

Carbon M3

Member
The only part I can explain is the ABS on the speaker box. Its the type of polymer that was used to make the speaker housing.

Acrylonitrile Butadiene Styrene

The rest I have no idea
 

gtf28

New member
gtf28 said:
Hi
E36 M43 12/1996
So my brakes are 100%, I replaced rear speakers( just swopped them out with 4" audison speakers), Drove off and while braking I noticed the brake pedal went in further at low speed than usual then a weird knocking noise came from the pedal and the pedal seems to be trying to push outward(only at low speed), brake pads are barely 3 months old, disks are just under a year old and no ABS warning light on dash. So its doing this weird knocking sound and trying force the pedal out with no effect on braking force(braking force is normal). Guy told me brake pedal travel sensor (he drove it and he is a mech), replaced it and still there, so a month later I disconnected the right speaker ( cant remember why) and boom it works 100% no knocking pedal takes less force to brake at low speed and feels stiffer, so im driving with a disconnected speaker, been to 2 auto-electricians, 1 says control module needs replacing(did not make sense to me) other one says go to BMW, phoned bmw Paarl, E36 is too old non of them has worked on 1, I must wait for the manager. So any ideas at all?
My speaker boxes does say ABS on them, but like I said new speakers are fitted in the box and top connector is plugged in (no change at all to connectors or wires cut/spliced). Put the old rotten speaker back into the car on the right side and still knocking and pedal goes in further at low speed. Diconnect only the right speaker and boom works fine. Please help.

*Update* pulled my headunit (maybe wires touching there) and put orginal BMW Business RDS in activated with my code and connected speaker did not resolve the issue although alot of other things started working like the ignition ding noise and other noises the car makes, unplugged speaker and then worked so headunit and wirering is not the problem since oem headunit has connector. Put all the oem speakers back and still no change.

*Update* Used bentley service manual to check all ground point, clened them and refitted them. Pulled dashboard out and checked all conections, used insulation tape to cover wires nice and neat. Checked all ABS fuses, speedsensors. Radio, speaker wires traced and checked and insulation taped the loom. Car's checked for moisture.
Btw found my chirp and door ding noise problem*fixed* alarm siren battery dead pulled on from a e46(the exact same siren btw). Still no change still knocking brake pedal at low speed while braking pedal as if pedal is too far for low speed. Unplugged rear right speaker and working fine. Not resolved almost 10hours work today. :skit:

*update* noticed a pump sound when the pedal knocks like a actuator or like the power steering pump sound just much louder, rear right speaker also plays a loud buzzing sound a second or two after the knocking occurs.
 

96328i

Member
Are you using the vehicles wiring? Have you tried running new speaker wires from the speaker to the headunit directly?
 

gtf28

New member
96328i said:
Are you using the vehicles wiring? Have you tried running new speaker wires from the speaker to the headunit directly?

Hi, yes the original wires speakers in original enclosure, havent tried new wires tho will try that. Will post update asoon as In done.
 
Best to get the codes read while speakers are plugged in but to hazard a guess, it might be your abs pump or a wheel speed or abs sensor being wonky?

Sent from Cape Town
 

gtf28

New member
francoishensen11 said:
Best to get the codes read while speakers are plugged in but to hazard a guess, it might be your abs pump or a wheel speed or abs sensor being wonky?

Sent from Cape Town

Will try to get hold of someone who can do the code reading for me. But going to put back old speakers and connect straight to headunit and test.
 
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