Another Speed sensor thread.

steveskeggy

Active Member
Joined
Jul 4, 2011
Messages
165
Car
S55 AMG
Here we go again with the dreaded speed sensors.
Quick(ish) history.
Car is 2003 S55 AMG.
Car off road for two years.
Car back on road.
Car passed MOT because on start up and in the workshop, the ABS light was not illuminated.
Offside sensor working, nearside not working.
Took to dealer, dealer got nearside one working, but offside not working anymore.
Changed sensor for Ebay special.
All fixed! No warnings, steering perfect, drove it up and down the road, yippee!
Then...
Got to around 30mph and ABS light kicks in, steering goes heavy, warnings on dash about ABS, BAS,CSI,CIA,SAS, you know the usual ones.
Went to dealer, dealer said its because its not a Mercedes sensor.
Paid £100 for Mercedes sensor.
Car worse, warnings come on straight away, steering heavy after about 5mph.
Weather now too cold to work on car, so driving around with heavy steering and no ABS, not good when conditions get slippy.

OK, so having put so many sensors on the car on the offside, and trying a different ABS BAS etc control unit, I have come to the conclusion that there is an open circuit in the wiring between the sensor and the control unit.
In particular, I am suspecting the socket that fits into the inner wing, which doesnt look all that healthy.
I have removed the socket from the wing for now because of the problem, and because pushing the plug from the sensor into the socket with the socket in place is difficult to say the least.

So, what I want to know is..
If I cut the socket out, and solder the end of the sensor wire to the two wires that come from the loom, will it cause problems because of changes in resistance?
(I am quite good at soldering).
The signal going to the sensor, is I believe 12v, others vehicles have stated 5v, but whatever it is, the signal coming out of the socket wont be huge, and before I try, I would like to know if it may or may not cause problems.
Thanks
 

Mattns

Active Member
Joined
Jan 7, 2017
Messages
165
Car
2005 S320 CDI
If It's just a connector so long as you solder the wires correctly 1 for 1 and don't cross them and insulate individually all should be good.
 

Neiltodd

Active Member
SUPPORTER
Joined
Jul 22, 2009
Messages
856
Location
moray
Car
c63 amg estate
You can get all those problems with just a low battery voltage and no other problems.
 
OP
OP
steveskeggy

steveskeggy

Active Member
Joined
Jul 4, 2011
Messages
165
Car
S55 AMG
You can get all those problems with just a low battery voltage and no other problems.
Its because the car has been stood for so long.
Moisture has got into the connectors and done damage, the worst one was on the ECU where it had rotted 4 pins away, luckily it was saved.
After I got the car on the road, there were new faults springing up quicker than I could fix them, but now I am driving it, there have been no new faults for months.
The two persistant ones are the speed sensor, and the secondary air pump relay fault.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top Bottom