Touran Rear Right Abs Wiring Problem - have VCDS codes - Wire colours?

[VAG-Abound]

Is D149 coupling point as you call it basically a small connector block containing the - abs wire?
Is D148 another small connector 5 containing the + abs wire?

Are these 2 connectors blocks both located at the side of the engine block in the engine bay and are they easy to access?
If they are 2 separate connector blocks as I suggest, why do you think D149 might be a potential weak spot over the other D148 connector block? Is it because it's in a different location that's more susceptible to damage?

Will Elsawin show me where these conenctor blocks are located, I can't seem to find it in their manuals.

I think you may be trying to get too detailed too early. I'd start be seeing if you get continuity from ABS unit to sensor. If so then don't worry where the connections are.

[Crasher]

I know the wiring is 99% OK on this one as the code changes from incorrect signal to open circuit when the sensor is disconnected, I should have the new ATE sensor in a minute.

[Crasher]

Typical ECP, order ATE and get Bosch, well at least it fixed it anyway, you would not expect Hella to produce a faulty new sensor. Now to look into the TPMS and air con issues.

[VAG-Abound]

I know the wiring is 99% OK on this one as the code changes from incorrect signal to open circuit when the sensor is disconnected, I should have the new ATE sensor in a minute.

Ooop, I meant OP. You mention a handy test for OP though: seeing if they get open circuit when unplugged.

[Crasher]

Ooop, I meant OP

Don’t worry, I realised that. I am quite surprised the new Hella sensor was faulty.

[TdiBlacky140]

I think you may be trying to get too detailed too early. I'd start be seeing if you get continuity from ABS unit to sensor. If so then don't worry where the connections are.

Problem is, it's a mates car and he doesn't live near by so I can't work on it the whole time or have access to it. That's why when it's here again I want to be able to do everything in one go, for example test for continuity and if there's none on 1 of the wires I want to know beforehand where the connectors are so I can start checking it straight away and not have to waste time there and then trying to look stuff up. It'd be different if it was my own car, I could test it bit by bit.

I'll see if the VCDS code changes to open circuit like with Crashers test if needs be too, handy tip.

I'm hoping the continuity test fails and that it's a broken wire as opposed to having continuity and it being an Ecu problem.

If the continuity test fails would it be a viable and reliable option to run a new length of wire the entire path from the sensor to the abs connector plug to skip out the entire need to look for the broken wire?

[VAG-Abound]

If the continuity test fails would it be a viable and reliable option to run a new length of wire the entire path from the sensor to the abs connector plug to skip out the entire need to look for the broken wire?

Do you mean lifting the trim, etc and just running a wire along the loom path? I think that's what you'd do anyway. Picking the original pair out of the whole loom to replace them would leave a much bigger mess.

Before hacking at the wires too much make sure the pins are present and good. My auxiliary heater was reporting "missing" and it was because the pin part on the 12V line had corroded and snapped in the housing, so had lost is connection to the wire behind it. Others have found pins pushed out of position, so a quick push back in gets things going.

In a similar vein, although they are "handed" I think the other side sensor may fit electrically. If not too much hassle I'd plug that in to help diagnose if it is a connectivity or communication problem. If you get "part here but zero speed" readings for same position rather than same physical sender I'd think about problem in ABS controller.

Getting the connectors apart to repair an in situ connector with proper crimp pins can be a real time-waster even with decent tools IMHE . If you're short of time small (usually clear) crimp+adhesive-shrink splices to use on stubs of the original wiring are an alternative worth considering for final connection. VAG do the splices at about £1.50 each, or get ten off of eBay for similar money.

Yellow is the traditional repair wire choice for VAG. If I was looking at it I'd get a yellow+trace reel of wire and run temporary connection under car using stiff garden wire twisted around stubs to route it reasonably safely to see if it fixes the problem. I'd plan a future full day to fit neatly.

[TdiBlacky140]

Had a go at this job tonight after doing some other non-related work on the car and had to bail out due to lack of access to the connectors on the abs pump.

I removed the battery and battery tray and could see the abs pump clearly but the Ecu connector is at the back of the pump practically against the bulk head and it's also against the side of the wing, I couldn't get a hand near the connector, I removed the arch liner to see if there was an access panel / window there but there is not.

I also think that even if I got the connector unplugged I'd have very little flex in the wires to be able to pull the connector up a little so as to make it easier to find the 2 pins and try put a multimeter on them. I think access seems worse than a Mk5 golf for example, I searched and seen a few pics of Mk5 golf and they do seem awkward but this Tourans position looks much worse.

I removed the rear drivers arch liner and followed the abs wire to where it disappears into the car and the outside sleeves and insulation all look intact.
I also disconnected the abs sensor and drove it disconnected to see if the VCDS fault codes changed and they did, I got 4 instead of 2 and they would all clear except 1 of the new codes which was "00287 - 012 - Electrical fault in circuit". This came straight back with the car not even moving. Also, the other new code which did clear was relating to "Mechanical failure".

Appreciate any feedback regarding whether the above has helped to definitely confirm it's a wiring issue and not Ecu?
Also, has any one got experience of disconnecting the Abs Ecu connector plug on a 2012 Touran and can you enlighten me please?

[VAG-Abound]

The connectors in the engine can be a swine to release. If you can get a half decent grip make sure you're pressing the release bit firmly and jiggle in as well as out to make sure it releases.

What were the 4 vs 2 faults? If it goes form implausible, zero speed, etc to not connected, low volts, etc then it suggests the wiring is OK enough to know when something is connected - so not open circuit.

How about working at the back on looking at alleged sensor output in VCDS while changing what is connected / disconnected to see if it is bad sensor, open connection or ECU? Depending on access, etc you may find it easier to leave sensors physically in position and take a pair of wires under car (safely) to connect RHS loom to LHS sensor,etc - IYSWIM.

[TdiBlacky140]

I listed all the 4 fault codes above in previous posts, the 2 that were originally existent and the extra 2 that came up with the sensor disconnected.

Orignal 2:
Incorrect Signal
+
Supply Voltage Terminal 30 - lower limit exceeded - intermittent


New 2 with sensor disconnected:
Mechanical Failure
+
Electrical fault in circuit