ABS fault?

[dpoorsBenz]

Can any body advise me. i think i have a problem (dirty buggers ;-))


My abs light comes on, but not as soon as i drive off, it's there when i start and i goes of when i pull away.

then about 5-7 miles later it comes on,

the abs works when the light is out (obviously)

but i cant seem to work out the problem, i had the brake sensors cleaned and all that,

just cant get me head around it.

Heeeeellllpp.

 

[television]

Does it do the same thing on every start and journey

Malcolm

 

[jberks]

It may be that a sensor is on the way out. Should be able to tell from a diagnostic.

 

[Stevie A]

I have read the OVP relay when faulty, causes the ABS light to come on. The ABS light comes on when the system detects a fault or if the voltage dips below a certain amount. If ABS light comes on when cornering or during sharp movement then probably OVP. If you've had hard starts or erratic idle revs then more than likely OVP.

 

[dpoorsBenz]

If ABS light comes on when cornering or during sharp movement then probably OVP. If you've had hard starts or erratic idle revs then more than likely OVP.

funny you should mention that, lately when idling it has been erratic,

and if i drive hard through the range and corner slightly sharper than is deemed normal the light comes on.

maybe thats where the problem lies,

how do i go about finding out if the relay is on the way out?

any help greatly appreciated

 

[television]

What you can do is to start the engine, and tap the relay,any change in engine speed at idle would show that the relay has dry soldered joints.
Its protects the ECU's the first beig the ABS/ESP. Some go and buy a new one,others have it soldered up(all joints) by TV eng;.

malcolm

 

[Stevie A]

It is 99.9% certain that the OVP relay needs replaced. It is beside the battery behind a plastic cover / flap, between battery and wiper motor area.
Just needs released and replaced, easy job.

Get a new one or get someone to solder it like Malcolm says.

 

[dpoorsBenz]

Correct wheel/tyre sizing

Having gone through all the suggestions,(btw thanks) nothing really resolved the problem, so i put it down to a faulty sensor and resigned myself to an £80 layout,

but the plot thickens :cry:

when i bought the car it was running on 7j Pentas? with 185/65/15 tyres.

just yesterday i got a set of original alloys, cossy rims i think, that are slightly slimmer.

when the tyre guy took the tyres off the penta's he said that they should not have been on that width rim, should have been 205's, so they were streched a little.

anyway put the tyres on the new rims and hey presto no abs fault, must have been a problem with the actuual rolling diameter of the wheel and tyre.

any thoughts?

will report back if anything changes, but fingers crossed

shaun

 

[television]

If you had ESP that would put the light on. the fact that the wheels have been taken off and on could also mean that one of the sensors is intermitent. see how it goes.

Malcolm

 

[dpoorsBenz]

Ovr?

I think i may have been a bit too previous with my assumption, it seems that the wheels may have had little to do with the abs fault,

now the light comes on but only after a sharp left turn only a left turn (wierd)

could this be the much maligned OVR that is causing my problems.

is so how do i go about testing it, i have seen various threads on this but the descriptions are varied and not very comprehensive.

just need to be sure,

obvioulsy i want to do things the most thrifty way i can

 

[Ian Brown]

Have you checked the wires going to the both front sensors?

 

[television]

As Ian's posting, wires to front are the most common fault.

Malcolm