Electrical and ABS questions...

[Chunklamb]

A few questions about general wiring and ABS looms...

I'm having issues with my ABS / TC / ESP failing on start up. I've had the fault read by a garage, who stated that it was a N/S/R ABS fault.

So from this, I went and bought a new ABS Rear Hub hoping that this would solve my problems... however, on plugging it in to the loom, I still have the same fault.

So I tested the resistance of the loom(s) all the way to the ABS Module in the engine bay, along their various stages. I was told that anything below 1.0 Ohm indicates a useable wire.

The rear loom ( sensors ) to middle box came back at 0.3 to 0.4 Ohms.

The Rear Box to ABS module ( I had to use a long wire to bridge the connection ) came back as 0.7 Ohms.

The Front wheel looms (sensors) to ABS module came back as 0.5 Ohms.

All ABS Wheel Sensors on the hubs, including the new unit, gave the same readout, however I failed to write these down! DOH!

So, basically, I'm asking if these values seem fine and I can now move onto looking at replacing the ABS module / ECU?

Are there any tests which I can look at doing for this before I fork out the money for an ABS module etc?

I drew a quick pic of the ABS loom layout, hope it makes sense??

Slide1.jpg

[Critch]

0.7 ohm is a high reading mate.

What voltage are you getting from sensors?

[Chunklamb]

In the wheel? I cant remember the reading off the top of my head, but all 4, plus the new sensor had almost bang on the same values... what should the senor readings be roughly?

[Critch]

Would expect an ac voltage of around 1v best tested using a scope.

But if their all reading roughly the same should be ok.

Do you have access to live diagnostics for the abs?

[Rebellion]

I'm sure I just read exactly the same post on a Saab forum, lol.

Have you tried disconnecting the ABS module in the engine bay and and spraying contact cleaner on the connectors?

[Chunklamb]

LOL yeah I posted it across a lot of forums!

I'm getting quite desperate and trying to save a few pennies lol.

If I'm honest, I really dont have a clue what Im doing... I just saw a thread on a Saab forum - http://www.saabscene.com/forum/threa...ault-Rear-Left...

and thought I'd give that a go...

[DTi Elite]

I did a 57 plate saab 9-3 at work & that was showing rear left , tested the wiring from the ABS sensors to the black box under the rear floor & both came back ok , tested from the box to the ABS pump & found high resistance on a blue wire that goes to the rear left , got busy testing wiring & narrowed the fault down .
the fault was in a section of loom where it comes out from the O/S/R floor to the connection block , the blue wire was heavily corroded & had green dust coming out it .
replaced this small section of wiring & all was ok .

[Chunklamb]

I'm getting 0.7 ohms all the way from the back, starting at the loom connection (detached from wheel sensor) to the plug for the abs module... does that sound about right?

[Chunklamb]

I just connected a 6 volt battery along the wire loom and I'm getting a perfect voltage?

[DTi Elite]

try tightening the pins in the ABS plug