I'm at a loss with this one.

 

 

So I've had the issue with ABS, ASR, Power steering, Hand brake lights on the dash illuminating. speedo not working. and no Comms to ABS module. Fuel gauge all over the shop when cornering or braking.

 

 

 

VCDS cannot connect to the ABS module.

The fuses on top of the battery are intact.

No. 25 fuse in fusebox not blown. 

Replaced ABS module with a second hand one. Exactly the same, still no comms.

Looking at wiring diagrams it would seem there are 4 lives to the ABS module. 3 from on top of the battery. 40,25,10amp. and one from the fuse box (no 25, 5 amp)

 

Testing the pins on the ABS module plug shows that the pin 1 (fed from the 40amp fuse) is continuous to the fuse. however pin 25 (25amp fuse) and pin 7 (10 amp fuse) are not showing as continuous back to the fuses.

 

Am I correct in thinking that from the fuses on top of the battery to the module is supposed to be continuous (not a switched live)??

 

thanks for any advice in advance

 

 

 

 

 

 

 

 

 

 

What year is the car?

 

You are correct that all the battery-top fuses (should) all go direct to their destinations. The feed from the cabin fusebox is the only one that shouldn't be live all the time, but only when ignition is on.

Are you sure you have the correct wiring diagram? Pin assignments at the ABS module seem quite different between pre- and post- '06.

The main lives are pretty obvious into the ABS module, they are the heavier gauge wires grouped at one end. Just check for battery voltage at them and of course check the earth.

We all know how the fuse on top of the battery has tripped people up, has done for years. Check for voltage in and out. Also worth checking the wiring loom as it curls under the module, very prone to water ingress.

thanks guys. 

 

I ended up untaping all the loom from the battery to the abs module, starting from the abs side. and found the 10amp feed (Red/White) wire has been rubbing on the top radiator hose spring band clamp! and worn right through. 

 

fixed that and hey presto, module is working perfectly

Nice work

Good to hear! Shame you didn't find that sooner but oh well!

:clap:

My abs came on, I broke the sensor trying to get it out, I also broke the sesor out of my spares and repairs Fabia trying to get that out, lol. Now my steering light is on as well, and my fuel keeps going from 70 miles to 45 miles on and off fuel light ❤️