Need serious help!!!!!

Hi again all. i am looking for some help tracing wires and voltages on the suspension ecu on a 2005 Discovery 3. From the tests we have done we think that it could be either a can bus or a signal issue. I am looking for a wiring pin diagram so that i can check out the wiring to and from the suspension ecu. There are 4 plugs on the ecu the code number is RQT 500100. If anyone can help out with this i would be very thankful.

Hi ya Kimsie. You can check here for Disco 3 info... https://www.dropbox.com/sh/2790fzg0...2ta/Discovery 3?dl=0&subfolder_nav_tracking=1

Unfortunately there is nothing there that helps. Could really do with full wiring diagrams so that i can trace wires etc. Have now found out that the ecu is not sending a signal to the compressor relay. Have voltage coming from the ecu when the car is running but its getting lost on the way to the relay. This is why i could really do with full wiring diagrams. Thanks anyway.

@gstuart would be the man who may be able to help you.

Cheers

I'm sure there's a joint that fails in the main compressor power supply cable, but can't remember much more than that.

What do the diagnostic codes show?

I can give you for LHD but i'm sure that the ECU connections to other units are the same. Attached relevant documents

Nodge68 said:

I'm sure there's a joint that fails in the main compressor power supply cable, but can't remember much more than that.

What do the diagnostic codes show?

Click to expand...

Cant get the codes as we can not access the suspension ecu. Can access all others but not suspension.

Also if i manually trigger the compressor relay the compressor runs. It seems as though its just lost the switch signal from the ecu to the relay

You wanted diagrams you have them now so you can investigate

@Kimsie....You asked for serious help and you now have it, as @sierrafery has responded. He is second to none on here for electrical issues !!!

Right so here goes. Doing some more checks this morning (voltage/earths etc) could only find 1 issue. For some unknown reason the voltage signal from the suspension ecu to the compressor relay is getting lost. After a struggle i managed to check the voltage from the suspension ecu and i have approx 12v coming from there but it is not reaching the relay to operate the compressor. Have also dropped my solus onto the car this morning and have the following:-

no comms to suspension ecu

No comms to instrument panel.

ABS Fault. No comms to instrument panel.

There do not seem to be any other faults listed on the vehicle.
Have done various live checks on the vehicle and all ABS sensors functioning properly as well as the YAW sensor and steering angle sensor.

Was a tech for 21 years with a small amount of knowledge on this type of car but this one has me stumped.

If the trigger signal is delivered by the ECU but not reaching the relay you must make sure it reaches the connector of the junction box (C0570-L pins 66-120) , if it does the problem is within the fusebox if not the wiring is interrupted somewhere cos it's hardwired unfortunately there's no clear view for that connector so you'll have to figure it out from it's shape and which are those pins cos there are many R and NR wires in it but it must be a logic in pin disposals or a mark to know where to start(in the diagram appears L and here is R cos it's about LHD and RHD but the connector and wiring colours should be the same...as about those fault codes you have instructions in the diagnostic doc i attached based on the actual code not on the description

Thanks very much will get round to checking that either later tonight or tomorrow