Fob Programming X308

I have been trying to program my fob on my 2000 Xj8. The car enters the program mode but doesn’t do the requisite chips or light flashes once in the program mode. I am assuming it’s an error on my part. Any suggestions , would disconnecting the battery do anything?

It’s impossible to say whether you’re doing something wrong without knowing what you’ve been doing. This topic was discussed in the past, so I guess that it’s a common problem. Take a look at this thread: [x300] X350 Re-programming key fob.

Or just go to the top header and click on the magnifying glass (search) and enter, “Key fob programming.”

Hi, The shift console light lights up after pulling on the stalk but I don’t hear a beep when it does. Step 3 gets me no beep. same with step 4. That’s the part that has me vexed. I’ve programmed my other XJ8 and XJ6 in the past but this one is giving me issues. Battery in the fob is at 2.97V.

Also noticed that the alarm doesn’t chip when I lock the car but he parking lights flash. Could it be some sort of alarm unit issue?

Don’t mean to “hijack” here, but was just about to post a thread asking how to synchronize our fobs on the X-308s. My 2000 XJ8’s battery went totally flat, and once I got her running again I took the opportunity to replace the old fob with a much better looking one (and yes, it’s of the same type and frequency as the old one, and has good batteries in it. Also kept my driver’s door open during the procedure). I followed “Phil’s” directions on that thread you linked to, but it didn’t do a thing – no chirping or console lights flashing. :frowning: Could there be another procedure for doing this on certain XJ8s? On our X-300s we turn the key on, driver’s door open, and push the valet button inside the console box a certain # of times to program the fob.

I have NO expertise on this topic, just an interest in finding a solution to the problem. I’ve never had a problem with my key fob, so I’ve not had to try to reprogram. As I stated in my first response, try going to the search feature and entering “key fob reprogramming.” Several different threads come up and one of them may have the answer. I’m not about to try reprogramming mine as an experiment because doing so would be kind of like futzing around with the carburetors on a perfectly well-running XK engine just to see if you understand the tuning procedures. “If it ain’t broke…”

Perhaps this will help, it took a simple Search on the new website using: X300 as the search term, taking about 30 secs.

It taken far longer to type up this post!

"Our 300 book does not have the program steps for a X308
transmitter. I tried this tonight and worked like a charm
the first time. I have to admit that on the way to the car
it seemed too simple/easy, and really didn’t think it would
work. This was needed as I had to replace the security
module. I don’t know how to add it to the book, but could
someone please add it. No tools needed and it saves $150
Lower portion of Key Fob programming of the four button
remote portion.
NOTE: When carrying out steps 4 to 6 below, all current
transmitters will be erased from memory. Ensure all
transmitters to be programmed are available before
NOTE: If at any stage two chirps are emitted, then an error
has occurred, if this is the case, the process has to be
repeated from step 1. When carrying out steps 1 to 7, ensure
no other transmitters are operated within range of the
system (which should not happen if you have all of the key
fobs with you in the car and no one else is playing with

  1. Open driver door (door must be open throughout the
    programming process).
  2. Pull directional indicator stalk to headlight flash
    position and hold.
  3. Insert ignition key and turn to auxiliary position
    (position I, first click), then release the directional
    Stalk right away.
  4. Within 4 seconds start to flash headlights five times by
    pulling/releasing the stalk repeatedly; at the
    fourth/fifth time you hear a chirp from the sounder and the
    PATS Red LED security dome will flash once).
    At this point all transmitters will be erased from the cars
    The next step will program all of your push button remotes
    to your car.
  5. NOTE: Up to five transmitters can be programmed. Now
    simply push the transmitter button (any
    of the four buttons) on the remote that is in the ignition,
    and then within 5 seconds push any of the
    four buttons on the next transmitter, etc. For each
    transmitter you do, it will be acknowledge by a chirp
    from sounder, and the PATS LED will flash once (Do not
    repeat the complete sequence if you make
    a mistake mid way as the first transmitter will be erased if
    you do).
  6. Turn ‘OFF’ the ignition and remove the key, (acknowledge
    chirp from sounder, and the PATS LED will
    flash once).
  7. Close driver door. Now check each transmitter�s
    functions on each of the four buttons on each of your Fobs.
    All should be working just fine. If not try again from step
  8. It may take two try�s to get it correct as the
    procedure is all about the speed, timing and doing it
    The PATS LED is the security dome in the middle of the dash,
    right up near the front window. If you make a mistake
    during the process, simply start all over from the
    If your car has all audible alarms disabled (as mine does)
    you won’t get the chirps, you just have to follow the LED
    flashing. You must flash quickly, then hit a button on one
    remote, then the other, then turn off the key. I would say
    it should take 5 seconds or less after releasing the stalk–
    Mark 2001 xj8, 1990 VDP (t-boned, laid to rest)
    TOPSHAM, ME, United States
    –Posted using Jag-lovers JagFORUM []–"
1 Like

Sorry the search term was “X300 book”

Ah, that may be my problem … the earlier post advised flashing the lights only FOUR times. I’ll try it again, but do it five times this time. Thank you very much for posting that, Neil. :smile:

O.K., I tried the “flash FIVE times” method, and still nothing. I’m beginning to think that the 2000 MY X-308s must have had some fob programming method that is different from what has been posted. :confounded:

My issue seems to be in the programming after the flashes. No chirp from the system but when I put the radio to AM I can hear a slight tone twice and then nothing. The fob doesn’t program but clearly some sort of signal is being transmitted.
Going to pull and rest the fuses and see if that has any effect along with pulling the battery cable. Then on to fixing the door cable on my other one when it warms up a bit.

Well, I dug around on the Internet and found this very informative and helpful guide to programming the X-308 fobs (and how to troubleshoot common problems with same). It looks pretty authoritative/official, as though it is copied verbatim from a Jag service bulletin or other official guide for the X-308 :thumbsup::

(btw, note that the instructions do NOT mention having to keep the driver’s door open during the procedure, unlike the provided instructions for programming X-300 fobs. Makes me wonder if keeping the door open might actually prevent the programming then (?). Also, the red light that flashes in the car is not on the dash, but in the vicinity of the shift lever.).

Also, I notice the author of that guide for programming mentions the correct fob battery as being a “CR-2032”. However, the old batteries in my fob were DL (Duracell) 2016s, which I put in the new one. :confused: Will check the Jag Driver’s Handbook to see which is correct before I attempt the programming again.

Well, final update time for me. I did switch batteries from the CR (or “DL”) 2016 to the 2032s and followed the programming procedure in the article I linked to earlier. Success! :triumph: :fireworks:

Some notes: after the fourth flash of the headlights, the red light by the shift lever did blink (accompanied by a faint couple of chirps), but I did flash the lights a fifth time for good measure. Also, it took me a few tries to get it “right”, apparently, and I noticed each time I tried w/o success it was necessary to open and then close the driver’s door, I guess to “re-set” things to start the process.

btw, I noticed my Driver’s Handbook specifies the CR-2016 batteries and in fact both my fobs contained that type of battery, although the linked article states that they should use CR-2032s. Not sure how the fobs worked before, as the CR-2016s are 3 volts and the CR-2032s are only 1.5 volts. I’m no Benjamin Franklin, but, recalling my basic electronics course in Vo-Tech school … 2 x 3 volts connected in series = 6 volts. I would worry that this excess voltage might damage something in the fob’s circuitry, but I guess not. (?) :thinking: In any event, I didn’t get a chance and didn’t want to risk programming the fob using 2 CR-2016s. My '94 XJS fob does use a single CR-2016 battery though, FWIW.)

I think the CR 2032 battery is more or less twice as thick as the 2016 IIRC so possibly the thinner ones didn’t make good constant contact at all times, also I think there was a change of frequency on the US fobs so whether these used different battery types I’m not aware.

Anyway Problem Solved!

You may have hit on something there, Neil. I noticed too that the older fobs seem to use a single 2016 = 3 volts and now the more modern models use two 2032s = 3 volts total. I wondered if there was some advantage (longevity perhaps?) to using two batteries instead of one to generate the same voltage … One difference I did notice is that the 2032s have a lot more in the way of microamps or some such vs. the 2016s (its printed on the bottom of both kinds of batteries). Maybe that’s a unit of storage, though, meaning the 2032s hold their charge better/longer than the 2016s? :thinking:

The water is getting a bit muddy for me now. Here’s what I just read on the differences: BATTERY SIZE AND CAPACITY
The CR2016 and CR2032 batteries both have a diameter of 20 mm, but the CR2016 is thinner, having a maximum thickness of 1.6 mm. The CR2032 is twice as thick, measuring 3.2 mm thick. The CR2032’s greater thickness means it contains more lithium-based chemicals and provides 240 milliamp-hours of service life, greater than the CR2016’s capacity of 90 mAh.

Because the CR2032 and CR2016 have the same voltage and diameter, it may be tempting to think the batteries are interchangeable. You cannot, however, fill a CR2032 slot with two CR2016s stacked one on top of the other, as this arrangement produces 6 volts, not 3, which may damage the device. If it fits in the device’s battery slot and makes a good electrical connection, a CR2016 can substitute for a CR2032, but it will have less than half the CR2032’s lifetime.

I believe that both the 2016 & 2032 batteries are 3v so stacking them in series in either case will present a voltage of 6v across the terminals, the issue will be a question of form & fit!

Otto is correct in saying that the 2032 s will have the capacity to last possibly twice as long or more. The only damage would be physical either by forcing them into the fob or intermittent or bad contact and therefore reduced voltage across the PCB itself.

20mm X 1.6mm = 2016
20mm X 3.2mm = 2032

BOTH are 3V
The 2032 will make the transmitter BLINK but will not transmit the signal to the SLCM.

You need 6V to make the transmitter work properly.

I have removed dozens of 2032 batteries from customers keyfob transmitters when they complain about them being INOP. Someone installed the WRONG battery!!!

You NEED to stack two 2016 batteries in the transmitter (6V) for the X300.

The X308/X100/X200/X202/X400/X350 keyfob transmitters need a single 2032 battery (3V).


Ahso the x300 fob is 6v and the x308 on is ONLY 3v!