Introduction
The designers of the Range Rover 4.0/4.6/P38A went overboard in the
alarm and security department, presumably thinking that thieves would
be keen on stealing such an expensive vehicle. Little did they
realize
that it would be one of the fastest depreciating vehicles ever, and the
alarm system would merely be another electrical headache for
owners. I
have heard horror stories even about quite new Range Rovers being
immobilized for weeks in the shop with alarm system problems.
This page
is an attempt to summarize accumulated owner knowledge on how the
system operates, what the most common failures are and how to recover
from them. Because the security system is so abominably complex
and
obscure, a better understanding of how it is supposed to
operate should
make fault diagnosis much easier.
Main System Components
BeCM, incorporating a Theft Alarm Unit (Z163) -- part of the BeCM
(under right front seat).
Remote Handset.
Emergency keys (supplied with later model vehicles only).
RF Receiver (in loadspace under right rear parcel shelf) 315 MHz
(North America), 433 MHz (UK and ROW).
Passive Immobilisation Coil (component Z270, surrounding the
ignition switch barrel) 1996 & later NAS & some other markets.
Driver's Door Lock and "CDL" (Central Door Locking) switch.
Door lock actuators and "door open" switches on other doors, rear
hatch and fuel filler.
Window and sunroof actuators and sensor switches.
Ultrasonic Volumetric Sensor (located at top of "B" pillar inside
the vehicle).
Inertia Switch (behind right footwell trim panel) shuts off fuel
and allows unlocking after a crash.
Under-hood alarm klaxon, and/or Battery Backed Up Alarm Sounder
("BBUS" -- some markets 1996 & later).
Central Locking and Alarm Arming
Central locking of all the doors can be done several different ways:
Pressing down either front sill locking button with the doors
closed will lock all doors.
"Slam locking" (pressing a sill locking button and then closing
the
door) will lock all doors -- only on vehicles up to mid-1996.
Locking the driver's door with the key.
Pressing the lock button on the remote.
"All Close" locking: Holding the key in the lock position for
over a second also closes the winndows and sunroof.
"Lazy Locking" (Most UK, Europe? but not NAS or Australia) --
Holding the remote button for
over a second also closes the windows and sunroof.
"Superlocking" with key or remote by a double turn of the key or
double press of the locking button on the remote.
Auto Relocking will occur if the vehicle is unlocked but no door
openings, ignition key insertion or turn-on, or movement inside the
vehicle are detected.
In cases 2 through 6 above, the alarm is armed to the "perimetric"
mode
in which it will be set off by opening any door, window, the rear hatch
or the hood/bonnet. Engine cranking is disabled and and
electronic
engine immobilization is activated (more on this below).
In case 7, the "superlocking" mode
energises an additional motor in each door lock actuator which
disconnects the sill locking buttons so they cannot be used (e.g., by a
burglar) for unlocking. If superlocking was done by the remote,
and the windows and sunroof
are closed, the ultrasonic volumetric alarm will also be
activated. (If
done by the key, a press on the remote locking button is still required
before the volumetric alarm will be activated). In this mode, the
alarm
will be set off if any movement of a person or animal is detected
inside the
vehicle.
Engine Immobilization
Whenever the alarm system is armed (or, on 1996 and later
models
when passive immobilization is enabled -- see below -- when the
ignition key is removed), the engine is immobilized. In this
state, the Engine Control Module (ECM) will not operate normally unless
it receives a mobilization code from the BeCM. Furthermore, if
some
clever thief jumpers the starter solenoid and manages to turn the
engine over, it will do no good because a crank signal is detected by
the
engine ECM (via the engine crank sensor which is normally used to time
the ignition and determine engine speed). This information is
sent to
the BeCM which puts an "ENGINE DISABLED" signal on the message
center on the dash and continues to make it impossible to start the
engine.
On 1996 and later models (UK, Europe? and some other markets,
but not North America or Australia), the
system was "improved" by adding a so-called "passive
immobilization" feature (enabled in North America and some other
markets) that activates engine immobilization whenever the key is
removed
from the ignition, regardless of whether or not the vehicle is
subsequently locked or the theft alarm armed. A "passive
immobilization coil" was added around the barrel of the ignition switch
to trigger a code from the remote handset when it is inserted in the
ignition, enabling remobilization (see remobilization section below).
Presumably the theory behind this "improvement" is that a thief cannot
start the vehicle even if you forgot to lock it and he can turn the
ignition switch on without a key. (NOTE: This wonderful feature also
requires you to leave the key in the ignition when changing the battery
to avoid immobilization. See Battery
Replacement page).
Photo
above right by Ron Beckett, showing ignition switch barrel on a 1995
model, with no passive immobilization coil but with "key in" switch and
wiring clearly visible. Cobwebs are due to this photo being taken in a
partially dismantled vehicle at a wrecker's yard.
Unlocking, Disarming and
Remobilization
The theft alarm is disarmed by pressing the unlocking button on the
remote. The RF receiver located in the right hand side of the
loadspace
conveys this signal to the BeCm which decodes it and, if the code is
correct, unlocks the doors and disarms the alarm. On 1995 models,
the
vehicle is then in an unarmed state.
On 1996 and later models with passive immobilization enabled
(UK, Europe? but not North America or Australia), if the key
is not inserted into
the ignition within 30 seconds of unlocking with the remote handset or
EKA procedure (see below), the BeCM reverts to the immobilized
condition. The engine remains immobilized until the remote/key is
inserted into the ignition, closing the "key in" switch and activating
a "Passive Immobilization Coil" (Z270) around the barrel of the the
ignition switch. The
electromagnetic field from this coil excites a receiving coil
in the remote key handset. If the remote is acting normally (for
example, does not
have a dead battery), it will then transmit a mobilization
signal to the BeCM via the RF receiver. The BeCM then disarms the
vehicle and
remobilizes the engine.
On all models, when the unarmed state has been achieved, the
BeCM transmits a mobilisation
code to the engine ECM commencing 48 milliseconds after the ignition is
turned on,
and until it receives a confirmation signal from the ECM telling it to
illuminate the "Check Engine" light (as an indication of correct
operation) and allows engine cranking when requested. In turn,
the ECM
enables engine fuelling and proceeds to allow all engine controls to
act normally.
Remote Handset Synchronization
and Desynchronization
The remote handset uses a "rolling code" algorithm, meaning the code
is
changed every time remote locking or unlocking is performed. The BeCM
stores the code sequence in its RAM and has a capture range of 100
codes after the previously received value, so should be able to remain
synchronized with the handset unless more than 100 attempts have been
made to operate the remote while out of range, or the remote's
batteries are removed or die, or the vehicle's battery dies or is
disconnected. That is the theory -- in real life it seems to lose
synchronization more often, such as when the vehicle's RF receiver has
been activated by other spurious sources of 315 MHz (or 433 MHz in
other markets) transmissions.
Resynchronization is accomplished by performing a key lock or unlock
within 30 seconds of requesting a remote lock, superlock, or unlock.
The BeCM senses the change in state of the "CDL" (Central Door Locking)
switch in the driver's door to initiate resynchronization.
On 1997 and later models (all markets?),
"friendly synchronization" is provided whenever the key/remote is
inserted into the ignition. The passive immobilization coil
around the
ignition barrel activates a pickup coil in the remote, causing the
remote to transmit an unlock signal to remobilize the vehicle.
Resynchronization Exception Mystery:
The driver's handbook, shop manual and ETM all contradict their own
instructions on resynchronization, stating that it cannot be
achieved by the above
procedures if the vehicle security system is "active" (Shop
manual) or "armed" (driver's handbook). In this case, you have to
resynchronize by the Emergency Key Access method (see below).
These
instructions do not make sense to me, since the alarm is nearly always
armed if the vehicle is locked. Perhaps it means if the remote is
desynchronized and the alarm has meanwhile been set off somehow, the
EKA procedure has to be used for resynchronization. Or, perhaps the
exception refers to when some malfunction is present. In any case,
probably the best method of resynchronization is to first unlock the vehicle
with the key so the alarm will be disarmed (if everything else is working
right), then perform the synchronization routine.
If the usual Synchronization
Procedure Does Not Work:
If after replacing batteries and attempting the usual resynchronization
procedure it still does not work, you can probably get the remote to
work again using a special procedure (formerly known only to dealers)
that is used to program new remotes. See the section on "Replacing and Reprogramming Remote Handset"
on the Replacement and Reprogramming page.
above procedures,
Emergency Key Access ("EKA")
Procedure
(Disarming Alarm & Starting Vehicle when Remote is
Lost or Fails)
Overview and Instructions
The EKA procedure is provided as a back-up method of disarming the
alarm and re-mobilizing the vehicle if all else fails. (For
another equally good if not better method see the "Key
in Position II" procedure below). It uses a
series
of locks and unlocks with the key in the driver's door lock cylinder.
From owner reports to date, this feature seems to be enabled on 1996
and later models in Europe, but not North America or Australia -- but see below for a generic EKA code procedure that
works in North America.
The manuals are vague and contradictory on when EKA might be
necessary
-- the shop manual says it is if you lock the vehicle with the remote
handset and then you lose the remote or it fails. (This is
understandable on models with passive
immobilization which cannot be started without the remote, but the
manuals are enigmatic on why this could happen on vehicles without
passive immobilization). You still need the key part of the
remote, or one of the spare mechanical keys supplied in
later model years.
According to the manual, if the remote has failed or been lost and
you
try to open the door with just the mechanical key, the alarm will sound
twice. (Of
course, this does not make sense because you should be able to get into
all models quite satisfactorily with just the mechanical key.
Perhaps
they are referring to situations when the remote has malfunctioned in a
way that upsets the BeCM, or the alarm has been set off for some
reason). If you then try to start the car, the message center
will display "ENGINE
DISABLED PRESS REMOTE OR USE KEY CODE". (This part makes sense on
vehicles with passive immobilization, as described above, or perhaps if
the alarm has been activated).
Make sure the doors, windows and bonnet/hood are closed, get out and
lock the car again with the key.
(Note: on 1996 and later models, you have to turn the key to the lock
position
four times for this step if the remote handset was not used to lock the
vehicle). Then turn the key the required number of times
according to the
following sequence. (At each step the side lamps warning light on
the
dash will light to show it has recognized the input).
To enter the first digit, turn the key the required number of
times to the unlock position.
To enter the second digit, turn the key the required number of
times to the lock position.
To enter the third digit, turn the key the required number of
times to the unlock position.
To enter the fourth digit, turn the key the required number of
times to the lock position.
Turn the key to the unlock position to unlock the doors. The
alarm
will now be partially disarmed; if you try to open the
hood the alarm will sound. After five incorrect attempts (3 for
1996
and later models) at this procedure, the BeCM goes into a 10 minute
lockout mode (30 minutes for 1996 and later models), during which time
the message
center displays "KEY CODE LOCKOUT" and further attempts at EKA will not
work.
The EKA code is supposed to be
on your "security card" but I don't
have
one for my vehicle and Staffan Tjernstrom, who first alerted us to this
information, mentions that getting it probably involves knowing your
dealer very well, and maybe a few pints of good beer! Alex Rudd informs
me that he has used the EKA method to recover from alarm problems, and
that in the UK you can present or fax your owner's log book (or email a
photo of it) to a Range
Rover dealer to prove ownership, and they will give you the code.
Update February 2005:
Confusion between LHD and RHD vehicles has been reported regarding this
procedure. Alex Rudd
from the UK reports "I have seen quite a few versions of using the EKA
code on the
net, most of which are wrong (I know, I've tried them all, and waited
hours during the EKA Key Lockout session!). The correct one to follow
is the version from the Range Rover handbook, which starts the key code
entry on the clockwise turn - most of the others I have read refer to
starting on an anti-clockwise turn, which then doesn't work." I
think this contradiction is due to the difference in key
lock direction between LHD and RHD vehicles (Alex's is a RHD model).
This was confirmed by Ian Gibree who had to use the EKA on his
Dutch-plated LHD Range Rover when interference from a cell phone tower
stopped his remote from working. He used the procedure in his handbook
starting withteh anti-clockwise turn and it worked. Thus it seems that the first
turn should always be to the "unlock" position.
Careful if your BeCM has been
Replaced: Now that some owners have changed the BeCM in their
vehicles, be sure you have the right
key code for your vehicle before you try this procedure. Alex
Zahariev reports (May 2009) trying it on his 95 model with the correct
code for his VIN, but after a few tries he got the "Key Code Lockout"
message and the shop had to physically cut the door open. It turned out
that his BeCM was a replacement from a later model salvage vehicle and
had been changed when his 95 had been flooded.
Generic EKA
Procedure on NAS
Range
Rovers
The EKA feature does not
seem to be enabled on US
vehicles, or some Australian ones,
and is not
mentioned in their owners' handbooks (but
see "rest of world" section below). However there does seem to be an
abbreviated version of the procedure available on NAS models, intended
to be known only by Land Rover dealers and using a generic code (1515)
for all
vehicles. One US owner with a 2000 Range Rover had his vehicle stranded
with a dead battery and no remote available, but when jumpering it got
the message "Engine Disabled, Press Remote". Since he did not have a
remote, he managed to reactivate
the vehicle using a variant of the EKA procedure that the dealer
confided -- the dealer
was fairly sure that almost all NAS P38's have the same EKA
code, which is:
Unlock once
lock 5 times,
unlock once,
and then lock 5
times. Aidan confirms that he
found out from Land Rover that the normal EKA is not applicable to US
spec P38A Range Rovers, but the generic "null" code (1515) is used. For
example, when replacing a BECM it asks for
the code and a null # is inputted (1515).
Ignatius Wong wrote in to say
the generic 1515 code he got from this page also worked on his 1996
Discovery when it its alarm system froze everything and prevented him
from turning over the engine. starting the vehicle.
Rest of World:
Kieran McCoey
reports from Australia that in
the case of his '97 build, '98 reg 4.0 rangie the EKA procedure does
definitely work (here we are speaking of the method requiring a special
code for each vehicle, not the generic code). "I've had to use it a few
times, when inadvertently parked next to mobile phone towers. (In fact,
there is a spot in a popular skiing town we frequent notorious for
immobilising Land Rovers!)." The method he used is a little different
from that described above. He describes the method given in his owner's
handbook
as follows: To initiate the procedure, one must first turn the key
anticlockwise (locking the car) 4 times. The 4-digit EKA code can then
be entered- first clockwise, then anti, etc. After all 4 numbers have
been entered, turn once more clockwise to unlock the vehicle, disarm
the alarm, and re-mobilise the engine.
Ove Sognnes from Norway reports that the generic code
worked on
his also: "Range Rover Norway didn't supply me with the correct
procedure for opening RR when remote is lost, but you did. Thanks
again.
Your procedure works perfectly on my 97 range rover HSE, open door,
lock 4 times, then starting procedure. Smashing."
Tip: Check Door
Handle If Vehicle Will Not Accept Code:
Shaun Dale,
an Autodiagnostician in the UK, had a P38 that would not accept the EKA
code to re-initialise the system. The alarm made a beep every time he opened the driver's
door. The problem was
traced to a sticky/corroded driver's door handle. If the door handle is
not fully retracted, the system will not accept the EKA. A squirt of
WD40 or similar and a vigorous working of the handle enabled him to put
the code in. This seems to be a relatively common symptom as it was
suggested as a possible cause by a main dealer.
Shaun notes that when the vehicle is immobilized, diagnosis is rather
hit and miss on early models such as the one he was working on. This is
because the vehicle will not talk to T4 diagnostics if immobilised,
whereas later models will.
Alternative
"Key in Position II" Disarming Procedure
An alternative procedure for getting the system out
of disabled mode is to disconnect the battery, and reconnect it with
the key in position
II. Steve Glover of New Zealand tried this with great success on
his 1999 Range Rover Autobiography.
"We recently
lost the only key that worked by remote on the vehicle. Our second key
had
stopped working remotely on the vehicle a couple of years ago, our
dealership
told us it was impossible to fix and we needed to buy a new one. We
used this
key to try the “key turn method” of EKA but to no avail no matter
how it was done it would not disarm the alarm. We then towed the
vehicle home with
the alarm tooting its head off. We kept trying the key turn method at
home but [it had no effect]." Steve offer the following details of how
he succeeded with the alternative "key in position II" procedure:
1/ Open the Vehicle manually
with the key (the alarm will be going off the whole time) and open the
bonnet (it
is extremely Important to leave the bonnet and the door open or you may
be
locked out).
2/ Disconnect the main 12 volt vehicle battery.
3/ Put key in ignition
and turn to position II.
4/ Reconnect the Battery.(window unset alarms will be
going off)
5/ Start the engine then push the lock and unlock buttons on the key
while the engine is running.
6/ Open and close all the windows to reset them.
7/
You are done.
For Steve, the method worked better than expected. It not only reset
the alarm and engine immobilizer,
it also made the second key work as a remote again! Steve even feels
this method might be the first one you try instead of the EKA
method. Mike Coleman
reports he tried it on his UK model when he did not have the correct
EKA code available, but it did not work for him. However Jimmy Kander
reports
that he tried it on his 1999 with great success: "I have a 99
black North American Range Rover. The stupid thing wouldnt start saying
engine disabled, check remote. The key turning did not work, but
disconnecting the battery and reconnecting it with the key in position
2 worked!"
Security System Fault Diagnosis
"ALARM FAULT" Message:
The most common cause of the "ALARM FAULT" message being displayed on
the
Message Center is failure of the ultrasonic sensor (located above and
to the side of the driver's head) which monitors the
interior of the
vehicle for intruders. The BeCM does a check on this sensor every
time
you switch the engine off and get out. If it does not work 5
consecutive times it generates the fault message when you have tried to
activate it by superlocking the vehicle. Replacement of the
sensor is
simple, but the problem can also be caused by a bad connection. The Ultrasonic Sensor Repair page gives more
details on how to diagnose and solve these problems.
"ENGINE DISABLED" Message:
This is displayed if an attempt is made to crank the engine (e.g., by
jumpering the starter solenoid) while the alarm is armed or passive
immobilization is in effect. Try pressing the unlock button on
the
remote; if this does not work you will have to use the EKA
procedure.
"ENGINE DISABLED PRESS REMOTE OR USE KEY CODE" Message:
This message can mean you have tried to start a vehicle
that has passive immobilization (e.g., 1996 and later North American
models)
with a malfunctioning remote or a dead remote battery. Or for
some
other reason when you are trying to start the engine, the alarm system
is still armed or is in a bad mood. The solution is to try the
EKA
procedure.
"KEY CODE LOCKOUT" Message:
This means you have made several wrong attempts to use the
EKA procedure to remobilize the vehicle; wait 10 minutes (30 minutes
for 1996 and later models) and try again; meanwhile carefully check the
procedure and call your friendly Land Rover dealer to make sure you
have the correct security code for your vehicle VIN.
False "IGNITION KEY IN" Message and inability to lock using
remote:
If you keep getting the "IGNITION KEY IN" message when the key is not
in, the BeCM thinks the key is in the ignition and is thoughtful enough
not to let you remote lock the vehicle in case you lock your keys in.
The microswitch that detects whether the key is in is probably staying
in the "in" state because of the center of the lock barrel being a bit
sticky. Often, just pushing on the center of the lock barrel will
cause it to pop out, fixing the problem. Otherwise, just try
reinserting the key and wiggling it in and out a bit to free up the
mechanism. Alterenatively, you might try puffing (with an
applicator)
graphite powder into the lock. Usually it will free itself up -- this
is much cheaper than buying a new lock!!
Inability to Disarm Alarm due to Failed, Lost or
Desynchronized Remote:
The security/central locking portion of the shop manual describes a
process (known as "Emergency Key Access" or
EKA) for disarming the theft alarm and remobilizing the vehicle in the
event
that the handset fails while the vehicle is in superlocked mode.
Each
vehicle has a four digit EKA code which is needed for the
procedure. The code is entered by turning the key the required
number of times in the driver's door lock according to a prescribed
sequence. For
detailed information on this and the recovery procedure see the EKA
Procedure section above. It might be worth a try if you are
having alarm
troubles.
Vehicle Battery Death While Vehicle Locked or Superlocked:
If you leave the headlights on or for some other reason the battery
dies while your vehicle is locked or superlocked, strange things happen
to the alarm system.
This seems to be one of the conditions that sometimes upsets the
security system and requires you to use the Emergency Key Access method
(see key/remote problems) to "reboot".
Another is when you jumper the battery to start the car, you can
easily get locked out. When the power comes back on, the BeCM
seems to
try to return the vehicle to the locked state. At least one owner
has
reported that after
gaining entry to his dead car with the manual key unlock, he put the
key in the ignition and then went out and hooked up the battery jumper
cables. Immediately, the vehicle locked him out. If all
your keys are
inside
the vehicle at this point the situation is fairly bleak. So
DON'T leave your keys in the vehicle if you
get out. If you absolutely have to, at least leave the door
or window open.
"Remote Battery Low" Message:
When you get the "Remote Battery Low" signal on the message display,
take heed and renew the battery, especially if yours is a 1996 or later
model with passive immobilization. On these models, if the
battery
dies entirely, the remote will not be able to transmit the code to the
ECU to
remobilize the vehicle and allow starting. (See procedure below under "weak reception from remote handset" before you give
up though).
For battery replacement
procedure
see Key/Remote Problems and Solutions Page
Inoperability of Remote Due to
Interference:
In the UK, a different frequency (433 MHz) from that in the US (315
MHz) is used
for remote locking and several owners have experienced trouble using
the remote to lock or unlock the vehicle when parked in places where a
lot of radio interference is present, such as at airports. Joe Jeffrey
reports a similar problem at his Petrol/gas filling station where there
appears to be a magnetic field
generated by an LPG pump which seems to
interrupt not only the handset signaling the locks but also the handset
talking to the BeCM when inserted into the ignition switch, preventing
the car from starting. (He managed to get around this problem by
manually locking the vehicle
with the key in the door lock when he gets out at the
station and then everything works fine when he gets back in).
The same radio frequency is also used for many remote control devices
in
Europe and Australia and there is the possibility that these devices
may cause interference. A partial fix became available in 2004 from the
UK
dealer network whereby the stock RF receiver (Part # AFR1953) was
superceded by a new one (YWY500010) which was less subject to
interference, but did not completely cure the interference problem.
Accordingly, this has since been superceded by an even newer design,
part number YWY500170. Owners with this latest update have not reported
any further problem. Photo at Right: RF
Receiver for alarm system, located on top of rear seatback support
under right rear
parcel shelf. It is accessed by removing the parvcel shelf trim. Rear
seatback latch is at top right of photo. Note
connection to window antenna at bottom of picture. Photo courtesy of
Ron Beckett.
Unexplained Battery Drain:
Several owners have complained of unexplained battery drain
when parked in certain areas like airports where a lot of RF energy is
present, or in large parking lots where other vehicles with remote
locking systems come and go. The problem is that the radio
interference (and/or radio frequency energy from other peoples' remote
locking handsets) gets received
by
the RF receiver which "wakes up" the BeCM from sleep mode, increasing
its current drain to about one amp instead of a few milliamps. Paul
Jameson of Avon Diagnostics
reports that all remotes use the same frequency, and the Range Rover
system does not bother to determine whether the code contained in the
RF signal is a Range Rover one before waking up the BeCM. The battery can easily
be dead after a few days of this. Meanwhile Jeffrey
Upton came up with his own solution (he lives near Logan Airport in
Boston and suffered this problem frequently). He disconnected the leads
between the window RF antenna and the receiver. In this condition the
remote still works fine as long as you are within a couple of feet of
the vehicle, but the effect of external radio interference is
eliminated! Andrew Walne came up with an even better idea -- installing
a switch to control the RF receiver. See much more info on mysterious
battery drain and Andy's cure on the Mysterious Battery Drain Page.
Weak
Reception from Remote Handset:
As the battery in the remote handset dies the signal it produces will
become weaker. If you want or need to use the remote habdset (eg to
disable the alarm) when teh barttery is weak, it is worth knowing that
the antenna for the RF receiver is at the front of the right rear
querter window glass. Holding the remote close to this location or even
against the glass will increase your chances of successful operation.
Failure of Remote Central
Locking due to Fuse Burnout:
Richard Corbett reports
that his remote central locking suddenly stopped working. His local RR
repairer mentioned a similar problem where one of the main fuses (60 to
80 amp ones) was blown but arced over again & was continually
making & breaking within the fuse. On initial inspection of
Rochard's fuses all looked OK, but when he held them up to a strong
light he could see that one of the ones that provides power to the BeCM
(BeCM fuses 12 thru 15) was actually blown, discoloured the plastic
holder slightly & was making & breaking contact. I replaced it,
problem solvered.
Unsolicited Locking and Unlocking
by Remote:
I have found that the remote can sometimes easily be trigered in my
pocket just by touching or bumping it. TSBartel reports a similar
issue: "My 2000 Range Rover 4.0 had a tendency to repeatedly lock and
unlock
the doors while driving and occasionally while parked. This problem has
happened twice since I've owned the car. The service personnel
swear
the issue is not the key fobs, but each time I've replaced the
batteries and button keys (both very inexpensive) the problem has
stopped within a couple of days and stayed corrected for a couple of
years. Try this before going on to other, more expensive approaches.
The batteries and rubber buttons should be replaced every few (3?)
years anyway. Change the batteries and buttons at the dealership, you
may need to reset the code on the fob - which is quite
simple." For detailed info on changing the batteries and nuttons, see
the key/remote problems and solutions page.
No Response to EKA Code:
I have heard one case where entering the EKA code did not have any
effect, due to a bad lock switch. Jacob
Lund had an unexpected battery drain and after replacing the
battery the engine was disabled/locked and the remote did not work. To
enable the engine and start the car he tried the EKA procedure without
success. Each time he tried to start the engine after having gone
through the EKA procedure the "Engine Disabled" message came up. ALso,
there was no response at all when he did the EKA procedure (no clicks,
no lights blinking, no signals on the dashboard, etc) only the central
locking system switching on and off. After four days at an authorized
service shop with a TestBook, the problem turned out to be the lock
switch (the one that recognizes the turns of the key when you "enter"
the EKA code manually).
Symptoms that may be due to Fuse
Box Problems:
A number of owners have reported problems (such as random cranking of
the engine by itself, inability to start the engine, gearbox failure
messages, error messages about the windows not set, and others) that
might lead one to believe thre are alarm or BeCM issues, but have been
traced to Engine Compartment Fusebox.bad connections and failures.
These are addressed on the Engine
Compartment Fusebox diagnosis and repair page.
Whenever the alarm system is armed (or, on 1996 and later
models
when passive immobilization is enabled -- see below -- when the
ignition key is removed), the engine is immobilized. In this
state, the Engine Control Module (ECM) will not operate normally unless
it receives a mobilization code from the BeCM. Furthermore, if
some
clever thief jumpers the starter solenoid and manages to turn the
engine over, it will do no good because a crank signal is detected by
the
engine ECM (via the engine crank sensor which is normally used to time
the ignition and determine engine speed). This information is
sent to
the BeCM which puts an "ENGINE DISABLED" signal on the message
center on the dash and continues to make it impossible to start the
engine. 
Inoperability of Remote Due to
Interference: