D3 oem handbrake not communicating

Hi,
My EPB has gone for the third time in my 10 years owing my ‘07 Discovery 3. I have bought an oem module not a genuine landrover part and had the garage fit it. The new part is not communicating with the car and won’t work at all!

Has anyone had this before? If so how do you get around it. The garage thought the module may be for a D4 not a D3 but the part numbers are the same as the genuine parts.

I was trying to avoid the £930 price tag the local specialist had quoted for the module. Any help greatly appreciated before I have to raid the piggy bank and cough up for a genuine part.

Thanks

The garage could be right. What was the fault with the one it replaced? Are all the fuses OK? have they checked for data voltage on the CAN connections? The address space and CAN framing is different on the D4 versions, so although it will be receiving and sending data, it'll be like speaking Swahili to a Walloonian...

The old one had stuck on so had to release it with the emergency pull. It had previously been repaired last time it stuck on and was beyond repair this time.
I will check if the garage have checked the fuses and CAN connections tomorrow.

Is there an easy way to tell if it is a D4 one?

Thanks

Not for an OEM one, no - you could always swap the control boards over, relatively easy without having to remove the module & Bowden cables. Check the power supplies first though.

Graculus said:

Not for an OEM one, no - you could always swap the control boards over, relatively easy without having to remove the module & Bowden cables. Check the power supplies first though.

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That could be a good idea! I don’t suppose you could point me in the right direct for any instructions or videos on how to do this can you? And how to check the power supplies first.
Sorry this electronic stuff is a bit over my head.

Thanks

Here's the wiring diagram, obviously you should be seeing battery voltage on pins G4, H4, F3 & F2. all measured to G2 & H2 (ground) and with the ignition on. The CAN voltage will fluctuate but should be around +2.5V on pins A3 & B2 and around -2.5V on pins A4 & A2, again measured to G2 or H2.
Don't probe the contact face of the connector, you stand a chance of damaging or spreading the contact receptacles, use some thin 'backprobing' pins, although you'll need to remove the connector housing shell for access.
Access to the interior of the module is relatively easy, remove the spare wheel, unbolt & remove the EPB support bracket, turn the module 180degrees so the 'lid' is facing you, remove the Torx 20 screws and prise the lid off - it's fixed with some silicon gasket sealer which will need cleaning out and re-sealing to prevent water ingress. From memory, you only need to remove the motor wires and the strain gauge connector, which is a 'Zero Insertion Force' type of connector similar to that used on laptop keyboards etc, there is a small bale arm that needs to be folded outwards to release the flexible connector strip. The PCB is held in with three or four Torx fasteners.

Just another point, if you have communications to all modules except the EPB, then it's likely the wiring is OK and it is indeed a later module - the reason being that HS CAN 'passes through' and if it wasn't allowing (or not capable of passing) messages through then you would have multiple other modules not communicating. If you disconnect the vehicle battery and measure across pins 6 & 14 at the diagnostic socket you should get 60 or 120 Ohms. 60 Ohms means the electrical CAN circuit is OK through the EPB (but still check the supply voltages).

Graculus said:

Just another point, if you have communications to all modules except the EPB, then it's likely the wiring is OK and it is indeed a later module - the reason being that HS CAN 'passes through' and if it wasn't allowing (or not capable of passing) messages through then you would have multiple other modules not communicating. If you disconnect the vehicle battery and measure across pins 6 & 14 at the diagnostic socket you should get 60 or 120 Ohms. 60 Ohms means the electrical CAN circuit is OK through the EPB (but still check the supply voltages).

Click to expand...

Thank you very much, that’s great information and very helpful.

I have just spoke to the garage and they have said the car won’t even start with the new EPB plugged in. I guess this indicates the HS CAN isn’t allowing/passing messages through?

Cm040 said:

Thank you very much, that’s great information and very helpful.

I have just spoke to the garage and they have said the car won’t even start with the new EPB plugged in. I guess this indicates the HS CAN isn’t allowing/passing messages through?

Click to expand...

Yes, exactly that - back to basics, check the correct grounds and power connections are there, if all OK, and there is CAN activity either side, then they could always remove the control board from the old module, wrap it in something insulating, like thick polythene sheet to insulate it and plug it on to the harness connector. This will restore comms and therefore enable the vehicle to start.