Lack of voltage....

[daminder]

Hi Guys,

A question for the spakies... how and why would there be a loss or lack of voltage on start-up causing the ABS function to de-activate.

It's a 190E thats had this problem for ages. I changed the over protection relay, but to no avail.

I'm pretty sure once in its life the car was probably jump started resulting in some frying action somewhere.

any help would be appreciated.

D

 

[piestore]

lack of voltage

Hi

99 times out of a hundred on this model its the fuse in over voltage protection relay or the relay itself, location mounted on the bulkhead behind plastic cover behind battary failing this you would have to follow the wiring diagram and check voltage supply. One last thought have you changed the relay mounted on the ABS unit ( under plastic cover) they also gave trouble.

 

[daminder]

Hi,

Thanks for the suggestion. The overhead protection relay has been replaced a few due to dodgy ones being fitted.

but this has'nt helped this particular problem.

I'm not sure about the relay on the ABS unit - i'll try and take the cover off and see. But if this was a gonna wouldn't the ABS not work at all.
My problem is sometimes it's great and everythings working fine, and then sometimes the ABS light comes on and stays on until the car is turned off and started again.

Is there any chnce that the ECU is damaged???

cheers

D

 

[kid-jensen]

What sort of voltage is it charging at? (Measure at the battery)

Any less than about 13v suggests alternator problems (rectifier, diodes, windings open/short, etc, etc, etc)

 

[Matt Crooke]

Danger...Danger....High Voltage...when we touch.......

Sorry, i couldnt help that.....

Ill get my coat.

 

[dieselman]

My problem is sometimes it's great and everythings working fine, and then sometimes the ABS light comes on and stays on until the car is turned off and started again.


This sounds like a wheel sensor or lead is faulty. The system detects the fault and shuts down until reset by switching off / on.
Try metering trhe leads whilst bending them.

It doesn't sound like an ABS unit fault as that would be continuous.