1995 Discovery 2.5TDi - ECU codes

Do the 300s have an ECU in any meaningful way?

P.

take a deep breath and plunge into

On or around Mon, 12 Dec 2005 22:57:46 +0000, "Paul S. Brown" enlightened us thusly:

only late autos, AIUI.

the older ones are all simple mechanical stuff. hence my questions in a nother fred about disco II and what it's like for a traditional nut-and-bolt mechanic like me to work on.

'course, the V8s have an engine ECU. But I doubt that's OBD either.

In message , Jacqui writes

If it is an auto with EDC then yes it will be.

Hi,

The Disco is a 1995 diesel manual and appears to have the OBD-type interface plug by the driver side fuse box. I have plugged in a PC serial to OBD converter hardware to my PC using VAG-COm software. It seems to recognise the hardware interface OK and goes off searching but then comes back with the message "not OBD compliant. The socket on the disco seems to be wired for OBD.

Help!

Tim

On or around 14 Dec 2005 16:07:58 -0800, "Jacqui" enlightened us thusly:

a 95 diesel manual is the same as ours and the only thing that might have an ECU is the alarm. The engine is controlled by a normal mechanical diesel pump, and the body electrics are nice old fashioned ones with wires for each job, AFAIK.

Later diesels with auto boxes got EDC - an electronically controlled pump, and that might be what the OBD connector is for.

but seriously, you're wasting your time IMHO with the one you have.

What's the problem with the car?

In message , Jacqui writes

You will (with the right hardware/software) be able to look at.

Alarm

ABS if fitted

EGR if fitted.

And that is it.

If the engine is playing around it is good old fashioned dirty hands that will fix it.

Good luck.

PS: I would not expect my LR diagnostics to be able to look at VAG stuff either.

Austin,

Thank you for your help. I have a problem with the ABS system. Sometimes the warning light goes off, other times it stays on permanently. I have replaced or tightened up all four wheel bearings as I understand that can upset the ABS sensors. The ABS system seems to operate even though the wheels are no where near to a locked condition when braking: the anti-lock chatter through the brake pedal happens just as the car is coming to a standstill. It is a bit of a worry because at the last minute braking efficiency drops. The only other thing I can add is that the SRS (air bag) light is also on with right half slightly flashing but I presume that is yet another issue?

Any further help would be much appreciated.

Tim

Marc,

Thanks for help. I have a problem with the ABS system. Do you know of any downloadable software I can use with my PC which will read the ABS LR codes?

Any help much appreciated.

Tim

In message , Jacqui writes

Tim

Disco 1 ABS is very hard to get into even with the right equipment.

It is possible that you will be able to get a flash code from the warning light, but you will have to look up the procedure for your age of vehicle.

Start with tapping in the wheels sensors as per manual and checking connections

Given the cost of wheel sensors on what is in effect a relatively old car a few of my customers have chosen to unplug the ABS ECU and run the brakes as normal.

Marc,

I thought I would go with your option but I cannot find the ECU. Tried under the dash behind the glovebox, under the passenger seat and to the right of the steering wheel but no luck. I have found an EGR ECU by the steering wheel. Any idea where else I should look?

Tim

In message , Jacqui writes

Are we talking a UK car?

If so then it is located behind glovebox. It is the biggest "box" behind there and has WABCO written on it. It has a very large ECU plug that faces you and is easy to unplug.

Good luck

Marc,

I have found the ECU, thank you. I have also been in touch with Wabco and they have given me the blink codes to get more diagnostic help. Do you know where the diagnostic plug is - I think it is supposed to be blue in colour to strap pin 14 to ground to get the ABS light to reveal the error codes? I see from the Wabco document that it has an ISO 9141 interface and pin 13 is the K - line. This all smacks of OBD compliancy so should I be looking for a J1962 connector rather than a

Tim

On a RHD it will be tucked up around the area of the fusebox. Can be tricky to find.

Look under the stearing wheel below the fuse box cover. There is a socket that looks just like an ODB connector. My 96 300 TDi has Electronic Diesel Control and this connector is where testbook is plugged in.

Peter

He already knows where the OBD socket is.

But that said it he has and OBD socket there is no real need for the blue ABS diagnostics plug

Marc,

Thank you for the info. As you say, I can see the OBD socket below the fuse box cover but uncertain exactly to which ECU it connects. When hunting for the ABS ECU under your guidance, I came across yet another OBD-like plug hanging about behind the Glove Box. It gave no clues what ECU that comes from.

Unlike Peters 96 Disco mine has plain old mechanical diesel pump control so it is not exclusively for that!

If only someone could give me the details of what is what with all these plugs and the "wake up" byte codes for this stuff I would go ahead and write a computer program to suck all the error codes out and done with it. Already got the baud rate issue sorted but certainly Wabco is uncooperative on bytecode information.

Anyhow, I will keep on searching for the blue plug.

Tim

In message , Jacqui writes

There will only be one OBD II plug that is the whole point. The OBD II plug connects to all ECU's in the car. But yours is a bit of a change over car.

As for writing your own software, I would not waste your time. wabco C Type 3 on that age of landrover is hard enough to get the fault codes from when using the genuine equipment. So you would be fighting a loosing battle.

Just out of interest.....If you can't find the ECU and you can't find the blue plug ......Are you sure you have ABS fitted??????

On a DIY basis you can get the flash codes once you have found the blue plug.

My diagnostic system does say the blue plug can be found under the seat but I have only ever found this to be true on Range Rover Classic.

The pin outs for the OBD II socket are:

Pins: 1,2,3,6,9,10,11,12---Not Used. Pins 4,5--Ground. Pin 7 Channel A bidrectional data(k line) for ABS and all EMS. Pin 8 Channel D Lucas 10 AS Alarm Pin 13 Channel B data in (L line) Used for airbag Pin 14 Channel B data out (K line) Used for air bag Pin 15 Channel A data in (L line) only used for wakeup on some systems Pin 16 12 volts power.

Save you self a huge amount of time and get it booked into a good independent specialist.

Marc,

Ok, Marc, I will give in with the software interface. I have finally fixed the system using a multimeter on the 35-way plug. Wabco were good enough to give me the pin-outs so I disconnected the plug, connected the multimeter to each of the sensor connectors in turn and drove around until I spotted an open circuit reading. Swapped out that sensor and job done! As you say a new sensor is outrageously priced but I managed to get a second hand one for =A370.

You have confused me a bit with your OBD pinouts. Are you saying this is how it is on my 1995 Disco or for OBD II later models?

Tim