2003/53 ML270 Fault code C1130 ABS,ETS,EPC etc

[Axcontrols]

Lights on the dashboard. Fault code say rear right speed sensor. C1130

Vehicle stationary. So not driving/moving. Just the ignition on. Clear the fault and then immediately read the fault and it's still there.

Replaced sensor with a known good one and the fault doesn't go away.

Checked the wire going up through the floor under the back seat and it looks fine. No chafing.

Another question on the forum mentioned something similar which he thought was related to moving his drivers seat (RHD) forwards/backwards. Does the wiring for the RearRight speed sensor go anywhere near the seat rails or seat adjustment switches?

Anyway where else I can look?

Oh. Not sure if this is relevant. Car drives normal. No limp mode etc. Just the dash lights on all the time so I'm assuming there's no ABS or traction control etc.

Thanks guys

 

[Uncle Benz]

You need to check the continuity of the wiring all the way back to the plug at the abs unit. The loom from the abs unit goes round a sharp 90 degree turn just after the exit from the large plug. It's common to find a chafed wire here at this turn. It's in the area behind and below the left hand headlamp

 

[Axcontrols]

You need to check the continuity of the wiring all the way back to the plug at the abs unit. The loom from the abs unit goes round a sharp 90 degree turn just after the exit from the large plug. It's common to find a chafed wire here at this turn. It's in the area behind and below the left hand headlamp

Thanks Uncle Benz.

I had the left hand headlight out. It's a UK RHD car so passenger side.

To the side of where the headlight was, behind the radiator, I see the ABS Pump? Big bundle of cable coming out of the back of that going straight down out of sight. Very tight in there so can't see where the loom goes and can't get my hand down there. Is that the loom you're talking about?

There's a fat bundle of cables in nylon mesh tube running along behind the back of the headlight and up over the inner wheel arch towards the fuse box. Is that the same loom that I need to follow back under the abs pump?

Access is really bad. Can't see down there and can't get my hand down there. Would it be easier from underneath? Or is there some trick to getting access to that area?

EDIT
I managed to get underneath and can see loom quite clearly. You're right it is a really sharp bend. But none of the covering is chafed. It's not touching anything to rub against. Doesn't look damaged at all.

It's difficult to follow the cable from the back right corner all the way to the abs pump. Under carpets etc. Any specific corners etc I should be looking at?

Thanks

 

[Axcontrols]

Anyone know the route that the cable takes? (RearRight SpeedSensor cable) I see it emerge into the cabin under the back seats and disappear under the carpet. I assume it goes along under the sill kick plates towards the front. But where does it go from there? Does it go into the engine bay by the battery and then sharp left along the firewall towards the fuse box? Or does it go over front right inner wing and left under the radiator?

Anyway idea where this thing goes would be really helpful so I can check grommets, kinks and chafe points.

Thanks

 

[Axcontrols]

Checked the wiring with multimeter end-to-end and it's not broken.

Checked the voltage in the white wire. 12v
Checked the voltage in the green wire, 9v

I'm assuming the sensor is a Hall sensor where the white is the 12v supply and the green is the return that would pulse between 0v and 12v as the sensor ring moves under the tip of the sensor. Is that how it works?

Checking the green wire and spinning the wheel it doesn't change. Permanently 9v. Shall I assume the sensor is duff after all? Or could the green wire be crushed against some other wire and picking up the permanent 9v from somewhere?