Nigel Hewitt

David Bexhall wrote:

> Tempted by a 1994 Range Rover 4.6 HSE at a local garage, but a test drive
> had to be aborted because the air suspension wouldn't shift from low so the
> car couldn't be driven at more than 35 mph. Is this a common fault, how
> expensive might it be to fix?

I think they run Microsoft Air Suspension. It's a GPF.

My 96 HSE runs OK for a while then goes into error mode
and refuses to take orders. If I leave it like that
sometimes it just drops to the bump stops. Last time
it did that was in Rugby leaving me to trundle home
to Brighton. That loosens your fillings.

Take it to the shop and they reset the fault code
and it all works wonderfully. After a few goes at
just rebooting the system for me like that (M$oft
style) they changed the pump. It ran longer between
faults. Changed the valve block. Best yet but it's
gone again. Note to self: ring Caffyns.

I'm not impressed by LR on that one. At least Caffyns
didn't charge me for the reboots. When it goes it's
lovely. Tows a 6meter RIB with a huge pile of dive
gear in the back. Beware of the liner slip problem.
The V8s trash themselves. Love the beast but wouldn't
recomend them.

Does anybody know anything about the protocols on
the Testbook port? I have an adapter but it assured
me it was 9600 baud and it isn't. My data-analyser
really isn't portable and the HSE won't fit into the
workshop. It doesn't do stairs.

nigelH

AndyC the WB

>>>>> "Nigel" == Nigel Hewitt <spam.news@nigelhewitt.net> writes:

Nigel> Does anybody know anything about the protocols on the
Nigel> Testbook port? I have an adapter but it assured me it was
Nigel> 9600 baud and it isn't. My data-analyser really isn't
Nigel> portable and the HSE won't fit into the workshop. It
Nigel> doesn't do stairs.

9600 baud it might be, RS-232 it ain't.

The physical layer protocol is similar to RS-232 and can be adapted
pretty easily.

Then you have to deal with the OBD-II protocol which could only have
been designed by a committee of lawyers (which, effectively, it was).

Finally you have to deal with the absolute crap data format of the EAS
ECU. This includes such gems as having to send a certain code within
a certain interval of powering on the ECU (not too soon, because it's
not ready, not too late, because it's carried on in non-diagnostic
mode), and tdealing with a data stream that appears to be the
information you requested at a random location ni a string of FF
bytes.

For that amount of effort, Rovacom Lite starts to look very good
value! Drop me a mail off-list (replace spam with andy) if you want
some more information.


--
Andy Cunningham -- www.vehicle-diagnostics.co.uk
Atheism is a non-prophet organization.
--- George Carlin

ADB

> 9600 baud it might be, RS-232 it ain't.
The baud rate is much slower than 9600.

>
> The physical layer protocol is similar to RS-232 and can be adapted
> pretty easily.
The physical layer is nothing like RS-232.

>
> Then you have to deal with the OBD-II protocol which could only have
> been designed by a committee of lawyers (which, effectively, it was).
Again, wrong. The EAS is the same ECU as used on Classics, long before
OBD-II was introduced.

>
> Finally you have to deal with the absolute crap data format of the EAS
> ECU.
Really? If this is Obd-II compliant (which it isn't) then that is a
dubious comment.

This includes such gems as having to send a certain code within
> a certain interval of powering on the ECU (not too soon, because it's
> not ready, not too late, because it's carried on in non-diagnostic
> mode),
Wrong.

and tdealing with a data stream that appears to be the
> information you requested at a random location ni a string of FF
> bytes.
>
That is simply not true.



> For that amount of effort, Rovacom Lite starts to look very good
> value! Drop me a mail off-list (replace spam with andy) if you want
> some more information.
>

AndyC the WB

>>>>> "ADB" == ADB <nospam@email.com> writes:

ADB> The baud rate is much slower than 9600.
ADB> The physical layer is nothing like RS-232.
ADB> Again, wrong.

What a constructive conversation this is becoming!

ADB> The EAS is the same ECU as used on Classics,
ADB> long before OBD-II was introduced.

No, the ECUS aren't the same. Similar, but not the same. The classic
ECUs date from the early nineties, around the time that OBD-II was
being developed, so there's not reason why they shouldn't be compatible.

ADB> Wrong.

How about actually sharing some knowledge and helping everyone rather
than just shouting that I'm wrong?

I admit that my knowledge is gleaned from others that know this stuff
much better than I do, but I don't think I've been that badly misled.


Andy


--
Andy Cunningham -- www.vehicle-diagnostics.co.uk
I did not dislike VMS in the brief time that I worked with it. Yes, I
thought it strange, but it looked like something humans could come up
with if they hadn't come up with Unix.

Nigel Hewitt

AndyC the WB <spam@cunningham.me.uk> wrote:

> 9600 baud it might be, RS-232 it ain't.
>
> The physical layer protocol is similar to RS-232 and can be adapted
> pretty easily.

I got that far. A friend who used to race cars gave me a box that
apparently translates but he assured me that it and the cable were
Range Rover compatible but he didn't have any other data. It's still
sitting in a box. I plugged it into the laptop and something was there
but it didn't seem to be 9600 coming out but it was cold and I
developed a bad attack of "don't care". Data coms is part of my business
so I don't really want to be doing that in my own time.

> For that amount of effort, Rovacom Lite starts to look very good
> value!

But not if all I'm trying to do is save myself a trip to the shop
to get the system 'rebooted'. I looked at the website and the
full kit for a P38A is virtually 1K. That's way more than I'd spend
when, if I whinge enough, they'll fix it in the end.

Thanks though.

nigelH

AndyC the WB

>>>>> "Nigel" == Nigel Hewitt <spam.news@nigelhewitt.net> writes:

Nigel> I got that far. A friend who used to race cars gave me a
Nigel> box that apparently translates but he assured me that it
Nigel> and the cable were Range Rover compatible but he didn't
Nigel> have any other data.

For the engine, it might well be. But that's all the OBD-II
specfication really covers. Incidentally, I'm assuming a P38A in this
discussion, but if you have a classic most of it still applies.
ODB-II is emissions related, which in practical terms comes to the
gearbox and engine ECUs only.

For classics, each system has it's one connector and interface logic.
For the P38A, there is a common diagnostic connector which actually
connects three different things - I forget the exact grouping, but the
EAS is on one pair of pins, some of the ECUs on a second pair, and the
remainder on a third. There's a common ground, +12V accessory power,
and a few odd pins like the power reset for the EAS.

Because the EAS connects to different pins on the connector from the
engine management, an OBD-II diagnostic system probably won't be able
to talk to it.

It's not as simple as "tell ECU 27 to reset faults", unfrotunately.

>> For that amount of effort, Rovacom Lite starts to look very
>> good value!

Nigel> But not if all I'm trying to do is save myself a trip to
Nigel> the shop to get the system 'rebooted'.

Depends how near the dealer is and how long they'll keep doing free
resets for you....



--
Andy Cunningham -- www.vehicle-diagnostics.co.uk
God Lite - all the thunder and lightning, but now with 50% less
theology, for those who seek the lite.
-- AdB in the scary devil monastery

Nigel Hewitt

AndyC the WB <spam@cunningham.me.uk> wrote:

> For classics, each system has it's one connector and interface logic.
> For the P38A, there is a common diagnostic connector which actually
> connects three different things - I forget the exact grouping, but the
> EAS is on one pair of pins, some of the ECUs on a second pair, and the
> remainder on a third. There's a common ground, +12V accessory power,
> and a few odd pins like the power reset for the EAS.

The thing in the passenger foot well. If it needs more than three
pins it's probably the wrong thing anyway as that is all this has.

> Because the EAS connects to different pins on the connector from the
> engine management, an OBD-II diagnostic system probably won't be able
> to talk to it.

> Nigel> But not if all I'm trying to do is save myself a trip to
> Nigel> the shop to get the system 'rebooted'.
>
> Depends how near the dealer is and how long they'll keep doing free
> resets for you....

All they have to do is fix the fault, bill me and I'm happy.
I keep taking it back hopefully but.....

Oh well. I'll forget that tack then.

nigelH

ADB

Do you know what the reoccurring fault is?



Nigel Hewitt wrote:
> AndyC the WB <spam@cunningham.me.uk> wrote:
>
>
>>For classics, each system has it's one connector and interface logic.
>>For the P38A, there is a common diagnostic connector which actually
>>connects three different things - I forget the exact grouping, but the
>>EAS is on one pair of pins, some of the ECUs on a second pair, and the
>>remainder on a third. There's a common ground, +12V accessory power,
>>and a few odd pins like the power reset for the EAS.
>
>
> The thing in the passenger foot well. If it needs more than three
> pins it's probably the wrong thing anyway as that is all this has.
>
>
>>Because the EAS connects to different pins on the connector from the
>>engine management, an OBD-II diagnostic system probably won't be able
>>to talk to it.
>
>
>> Nigel> But not if all I'm trying to do is save myself a trip to
>> Nigel> the shop to get the system 'rebooted'.
>>
>>Depends how near the dealer is and how long they'll keep doing free
>>resets for you....
>
>
> All they have to do is fix the fault, bill me and I'm happy.
> I keep taking it back hopefully but.....
>
> Oh well. I'll forget that tack then.
>
> nigelH
>
>

Nigel Hewitt

ADB <nospam@email.com> wrote:

> Do you know what the reoccurring fault is?

Once they said there were both high pressure and low pressure flags set.
I assumed this meant limits exceeded but I didn't ask. The stupid system
works but when it is in this mode it refuses commands from the switches
so you bounce around at whatever height it currently decides on by
feeling its seaweed. It's due a service soon anyway...

nigelH

ADB

Ask them for a print out of the fault memory.
The EAS does not store a fault regarding high pressure and low pressure
flags.





Nigel Hewitt wrote:
> ADB <nospam@email.com> wrote:
>
>
>>Do you know what the reoccurring fault is?
>
>
> Once they said there were both high pressure and low pressure flags set.
> I assumed this meant limits exceeded but I didn't ask. The stupid system
> works but when it is in this mode it refuses commands from the switches
> so you bounce around at whatever height it currently decides on by
> feeling its seaweed. It's due a service soon anyway...
>
> nigelH
>
>