Scan Tools, TestBooks and
Computer Code Access Tools

TestBook
and T4
Aftermarket TestBook/T4 Alternatives
OBD-II Scanners
Home Made Solutions
(Photo: Autologic System, courtesy of Atlantic
British)
Testbook and T4:
The coming of the P38 model with its all-pervasive electronics and
dozen or so ECUs brought with it the advent of the "Testbook" made by
Hewlett Packard, which
dealers use to access the
fault
codes and other information for such systems as the air suspension,
cruise
control, transmission, ABS/traction control etc etc. This system
consisted of a ruggedized notebook computer with a touch screen, a
cable and connector for the 16-pin OBD-II compliant connector under the
glovebox, and suitable software. It accesses
many
more vehicle functions than standard OBD-II systems -- anything that is
computer controlled, which is nearly everything -- the
engine, transmission, transfer case, suspension, BeCM, ABS, cruise
control,
and on and on. Originally, the system was not even available to anyone
outside the dealer network, making it doubly frustrating when you run
into
the notation "Refer to Testbook" in the factory repair manual.
Originally costing $30,000, the Testbook system was well out of reach
of most independent shops, let alone individuals.
When Hewlett Packard got out of the automotive diagnostic business
in 1999, Land Rover contracted with another company, Omnitec, to
produce a more upt to date system called the T4. Due to legislation in
the US forcing auto manufacturers to make their technical and
diagnostic information available to independent shops as of October
2003, the T4 system is now available to the public through Omnitec
as their "T4" diagnostic system. The cost is £7,785 or about
US$12,000. Also available from them is an optional hand held T4 tester
covering 99-on models.
Aftermarket Testbook/T4
Alternatives
The unavailability and outrageous cost of the Testbook system
created a market for independent firms to develop their own diagnostic
software by reverse engineering the Range Rover system. These are sold
less expensively -- in the $2,000-10,000 ballpark, and the main
contenders are the Autologic
Diagnosis System and the Rovacom
system, both from the UK.
Autologic Diagnosis
System:
The Autologic Diagnosis
System is another aftermarket TestBook equivalent from the
UK. In
the US it is
available through Atlantic
British, who also provide training seminars on its use. Aimed at
local garages rather than individual owners, the complete system
(costing significantly less than the T4 system) covers all late model
Land
Rovers. It includes extensive help pages and internet updates. (See
photo at top of this page, courtesy of Atlantic
British).
Black Box Solutions:
The Rovacom system
by Black Box
Solutions was the first aftermarket equivalent for the "TestBook"
to become
available, and was claimed to be even better than the TestBook. It was
certainly more
portable. It used a rugged custom case and hardware with a 12 inch
touch
screen, and drew its power from the vehcile's diagnostic connector or a
12 volt jack. The unit came with all the software installed for the
various
Land Rover models, but you could pay for only the ones you wanted
activated.
The basic unit with no software activated was about £2,000.
Thus, you could get a system customized to cover all the systems on
your
particular Range Rover P38 for about £3700 ($6,000). Black
Box Solutions later started selling used Rovacom units for up to 50%
off, bringing them
down
to the £4,500 range ($7300) for units with software activated for
all models. In the US the Rovacom system and its descendants is
available through dealers including Rovers
North
(email@roversnorth.com and ask for Arthur or George) or British parts
International
(Phil Prince, Phil@britishparts.com).
OBD-II Scanners
The Range Rover 4.0/4.6 complies with the
OBD-II standard and ISO-9141. OBD-II scanners are now available for
$100-200 and plug into the 16 pin connector under the passenger side
dash.
Although it will not tell you everything the dealer's $15,000
"Testbook"
does, it can give you a lot of information about the engine and
transmission
fault codes specified by the OBD-II standard -- for example it will
tell
you why that pesky "Check Engine" light has come on. One low cost
system
is a $122 OBDII
Automotive
Scan Tool Browser for your notebook computer is available from Alex
C. Peper, 67 Scotch Pine Dr., Islandia, NY 11772, complete with OBD-II
connector and cable. Partsamerica.com
sells the hand-held Equus 3100 OBD-II code reader for $114.99. Actron makes
a
convenient hand-held scanner that works on all American and Import
OBD-II vehicles and is sold through
JCWhitney.com
for about $159. The same vendor also sells low cost scanners from Auto
X-ray and
Equus. Danny
Ledford reports that TRW has a scan tool called the Laser 2000 that
is very affordable. He says it does engine management, ABS, and
electronic
air, and works on new OBD-II and older serial ports. Tradervar is another low cost
source of scan tools.
For more information on OBD-II scanners, software and gear see the RangeRovers.net Diagnostic Equipment forum.
Home Made Solutions
Ken Metcalf has a '93 RR with
air suspension which he
bought (cheap)
with the Air Suspension on the bump stops and the ECU in fault
mode. He has been chipping away at arranging his own "Testbook"
to
deal with this but is still trying to figure out the VCSI (Vehicle
Serial Communications Interface) and cable that goes
between the serial port on the computer and the Air Suspension ECU.
He thinks that the VCSI is an
ISO9141-2 box with K line and L line outputs but it is not clear which
connects to which pins on the diagnostic connector. Another
puzzle is that the Rover cable between the VCSI and the ECU has a push
button that initiates communication.
IN 2004 Ken offered the following notes on his efforts to figure out
the system:
"I am still trying to unravel the puzzle of how to interface
an ordinary PC or notebook (loaded with Testbook software) to the Air
Suspension ECU on my '93 RR Classic. But I am sure that once
access to one of these systems is figured out, the rest will be plain
sailing. For what it's worth, here are some of my observations
(with regard to the Classic Air Suspension ECU - take them at your
own risk! ):
- External to the PC/Notebook (and
connected by a special serial cable) is the VCSI (Vehicle
Communications Serial Interface), which then connects to the ECU with
another special cable that has the appropriate diagnostic
connector. Testbook hardware information only says that the VCSI
conforms to ISO9141 standard and can achieve a baud rate
synchronization from 10 to 10K baud.
"The physical drawing (i.e.
a picture, not a schematic) of the cable that connects the VCSI to the
ECU terminates at the ECU end with a diagnostic connector, a hand -held
push button and a wire with an uninsulated alligator clip on it
(probably for connection to chassis ground).
When you look at the Testbook
software loaded on a PC, it says to push the hand-held button to begin
communication. Looking at the other cables and connectors used
for the various ECU's, it is only the Air Suspension that has this
push-button arrangement to start communication. ISO9141 uses two
communication lines a K line and an L line - although mostly just the K
line is used ("single wire communication"). This leaves me to
speculate that the L line is routed through the push button and is only
used to "wake-up" the ECU. The ECU has two pins for connection to
diagnostic equipment - pin 17 and pin 35 - which pin is the K and which
is the L, is not clear; although pin 17 has wire colour abbreviation
"WK" and pin 35 is "WLG" - this is either: 1) a clue, 2) a red herring,
3) a coincidence - take your choice! Take note, however, that the
diagnostic connector for the fuel injection ECU also uses
these same peculiar wire colour codes, and the ABS has a "WK".
"The big problem now is figuring out
the VCSI and it's protocol, compounded by the fact that any ECU
built before 1996 is pre-OBD2 and can have any one of a number of
unique protocols. There is a very active forum at www.scantool.net - do a search
on "ecu" or "range rover" in the forum and you will see that that
there are a number of people chipping away at this. On this
forum was posted a link http://members1.chello.nl~t.bloem/defender/testbook/testbook.html
that supposedly shows the diagram for the original Rover VCSI, but it
is in German and seems to be the usual opto-isolator type ; also it is
for the more modern vehicles that have diagnostic connectors that
conform to OBD2. www.elmelectronics.com
is somehow associated with scantool and their site makes interesting
reading too. Jeff Noxon has designed a very simple RS-232
/ ISO9141-2 optoisolator interface - the details are available free
online. Ross-Tech is another good source of information on OBD".
Meanwhile, Ken reports that you can purchase Rover
Test Book software (that will go on an ordinary PC) for US$250 at www.the-land-rover.com
- look under "Manuals - OBD". Bruno at www.the-land-rover.com says
that they are working on a DYI kit for the VCSI. Jeff Noxon
has designed a very simple RS-232
/ ISO9141-2 optoisolator interface - the details are available free
online. Ross-Tech is another good source of information on OBD".
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Page revised February 2, 2012