ABS (speed sensor)

[karlk]

evening all, what a great day i have had (not). Does anyone know if the ABS fault light activates if there is conflict with the autobox and speed sensors. I have had fault codes read and the only fault codes reocurring is speed sensor, no ABS fault light showing but the ABS is working and does show a fault if i disconnect anything on the ABS circuit. The valve block and conductor plate in the box is brand new from mercedes so should not be any problems there. Any ideas.

cheers

karl

 

[hardtop]

what car is it karl

 

[karlk]

1997 c180 with the 5 speed auto.

 

[hardtop]

it might be a sensor on the way out i think the light wont come on till it packs up

 

[karlk]

thats what im hoping for, one of the speed sensors breaking down. Gonna change the diff box oil anyway so i will start by replacing the rear sensor as there is only 1 at the rear. then clear the codes again and see what happens.

 

[television]

You do have a speed sensor on the front

http://www.detali.ru/cat/oem_mb2.as...417717.418&CT=F&cat=44V&SID=54&SGR=663&SGN=21

 

[karlk]

hi malcolm, thanks for that drawing. still waiting for my sailing parrots master copy of WIS to turn up. Theres nothing in haynes for the speed sensors electrical circuit. I have already removed the rear sensor ( in pieces ) 100% sure it was the original fitted one, real B*****d to get out, took a lot of workshop tricks to remove but done.

 

[BABASON]

Sir,

Iam guessing here but this speed sensor fault you read was in gearbox control module, No ???

Because i suspect you r confusing abs speed sensor with gearbox speed sensor in gearbox

 

[television]

Sir,

Iam guessing here but this speed sensor fault you read was in gearbox control module, No ???

Because i suspect you r confusing abs speed sensor with gearbox speed sensor in gearbox

Not quite, the gearbox needs a speed sensor signal, as does the ESP/BAS. the ABS has its own wheel speed sensor in each hub, the road speed sensor is always in a front wheel

 

[karlk]

If the autobox speed sensor is fitted to the conductor plate then this should be working ok as it is brand new. i thought the gearbox and road speed sensors work in tandem, communicate, for correct gear selection. If not then im baffled. If anyone knows please help.

cheers

karl

 

[colechelle]

If the autobox speed sensor is fitted to the conductor plate then this should be working ok as it is brand new. i thought the gearbox and road speed sensors work in tandem, communicate, for correct gear selection. If not then im baffled. If anyone knows please help.

cheers

karl

the speed sensor in the gear box would not light the abs light, it would put a fault in the ETC control module and that in turn would put the engine light on, go with Malc on this one RPM sensor going from what you have said!!

 

[karlk]

Malc (television) could you please give me any info you have on the rpm sensor. i.e. where it is.

cheers

karl

 

[colechelle]

if you find somebody with a star machine you can check actual values on each sensor at the same time, best way to check!!

 

[colechelle]

each hub, going to the inner wings where they plug in!

 

[karlk]

thanks colechelle. I have been using a snap on diagnostic code reader and a carsoft reader. the carsorft reads rpm fault and the snap on reads speed sensor, are they reading the same fault.