Dear All,
Any thoughts? June 1995 200K miles central locking bu**ering about. In last few years for various reasons have upgraded RF receiver, drivers side door station and fob. Now the problem appears to be the car is immediately forgetting any synchronised fob. So I can go through all the EKA code setting and the car will unlock but as soon as I go to use the buttons on the fob again after a reset it doesn't respond. The latch in the drivers door is a new one a few years ago but has been fiddled with by a paint shop. the rear passenger door locking buttons are a bit tight and not often used these days. I've done the dealers quick re-synch holding teh buttons on the fob with the key in the lock until the light flashes fast and with the key in the ignition the led does come on. I have two fobs, one regular one and one a backup. the problem first came to light out of the blue using the daily fob, which the car no longer recognised but the backup worked for about a week, then its started happening with either.
So any pointers greatly appreciated. I'm thinking the RF receiver first?
You were turning the key in the lock while pressing and holding the fob buttons? You need to turn to lock and hold there while you press the lock button, return to centre, then turn to unlock, hold there, and press and hold the unlock button. If you can successfully enter the EKA then the latch microswitches are fine so that isn't your problem.
The upgraded receivers have been known to fail though.
Dear Richard,
Thanks for such rapid response. Its bl**dy cold out there and off course I didn't realise that there is a dedicated alarm sounder under the fuse box! I'd disconnected the first horn thinking that was the source but the next time it still honked away. How can it still make a noise upsetting the neighbours? I found and disconnected the second horn, but it still did it, how can it still be making a noise upsetting the neighbours? That's when i located the dedicated alarm horn. Anyway all silent now.
Yes the fob was rotated as you say.
What I have now noticed is that after an EKA reset if I turn the key in the door lock to lock the car i hear clicks and clunks from all four doors but then if I turn it to unlock only the drivers door unlocks, the three others do not operate. So maybe its a drivers door microswitch problem?
Would a drivers door microswitch problem play havoc with everything else?
If the CDL switch had died it is possible that it wouldn't cause the other door to unlock. But, if the CDL switch had died you wouldn't be able to enter the EKA as that uses the CDL switch to tell the BeCM which way you are turning the key.
If it needs the EKA putting in, it will only unlock the drivers door. Once the EKA is in and accepted, then they should all unlock.
Like I say, there is a tiny surface mount 5V regulator in the upgraded receiver which has been known to fail. I know Marty has repaired a few of them. Do you have an earlier one you can put in to try?
Gilbertd wrote:
Like I say, there is a tiny surface mount 5V regulator in the upgraded receiver which has been known to fail. I know Marty has repaired a few of them. Do you have an earlier one you can put in to try?
Dear Richard,
I don't unfortunately. I see from the Rangerovers.net site Marty is offering a replacement RF receiver but he's out of stock at the moment.
I've also notice that when the car is unlocked the passenger door tabs don't shoot up as vigorously as they used to, could resistance in those mechanisms be part of the problem?
in the meantime i've examined my green spot receiver, no obvious sign of anything burnt out.
It isn't a replacement receiver, it's a filter that plugs into your existing receiver and updates the earlier ones to Gen3 performance. Gen1 was barn door wide so would respond to any transmission between 420 and 440MHz so would keep waking up the BeCM and causing your battery to go flat. Gen2 is a lot better but would still respond to a signal on 433MHz and wake the BeCM but not unlock the car. Gen3 checks for a valid code before waking the BeCM so preventing battery drain problems, the filter does the same, blocking anything that isn't a valid P38 lock or unlock code.
I've had a look at a Gen3 that wasn't working and, as a test to confirm it was the receiver, I pulled the one out of my car to try that and it worked perfectly so the owner just got a used Gen2 to fit instead. The Gen3 looked fine and I ended up sending it to Marty so he could have a play with it and it was him that said he'd found a few others that had failed with no immediate signs of anything burnt.
So the bottom line is, you still need a working receiver. I've got a Gen2 (blue spot) with one of Marty's filters (a prototype one he let me have to try and see if I could break it) on mine while he Ascot has a Gen2 without a filter. On that one the BeCM will be woken up every time either my car or the other half's SLK are locked or unlocked as it will respond to the signals from their fobs but it still takes about 4-5 weeks for the battery to go flat.
I didn't have a problem with a flat battery on my P38 for many years when I lived in the country but when I moved into the town & had to park the car on the street I encountered problems. I had the RAC out several times & became very adept at entering the EKA code with the key before I discovered from my forum researches that it was the RF receiver. I had a Gen 1 of course. I tried a Gen 2 which was better but the battery was still going flat if I left the car for more than a few days. I bought an alleged Gen 3 from eBay which was no better then the Gen 2 so I suspect that it was really a Gen 2 that had been 'upgraded' with a green dot sticker. I finally opted for a brand new genuine Gen 3 that cost me about £250 & completely solved the flat battery problem.
Well, after years of bu**ering about with my own 1995 (Gen 1 Rcvr. fitted) I just fitted a "12V Remote Relay" too: That allows me to turn the power to the receiver off/on .... when I want to use the car with the OEM fob... (Yes, that does mean using a second fob for said Remote Relay) but it was a cheap/effective fix - and also saved a fortune in (flattened) batteries due to all that irritating constant/random BeCM wake up of course......
PS: A reminder that the GEN 3 Rcvr. is physically different from the GEN 1 & 2 so if anyone buys a GEN 3 it is not just an (expensive) Green Dot of course. Ask them for photo inside the box .....!
There's also two different versions of the Gen2 if you look at the internals but the performance is very similar in as much as they pass whatever is received through to the BeCM whether it is a legitimate code or not.
Richard: IIRC the Gen 1 was an open PCB, Gen 2/a was also open board, Gen 2/b put the RF stuff in a can (which was clearly wishful thinking.....) and Gen 3 has that second small (RF) board perpendicular to the main board......? Still not quite sure how (or if) they got EMC Certification (Susceptibility) for either Gen 1 nor Gen 2s though...... Dire...
EDIT: Found the/a link from 10+ years ago about this scam/issue; https://mez.co.uk/page12.html
-and back then a GEN 3 was a mere £150+VAT !!
FWIW: The 'whole sorry saga' was reported thus
https://www.rangerovers.net/threads/the-updated-rf-receiver-ywy500170-to-solve-battery-drain.31919/page-2
Until some of the contributors were banned.............
Dear All,
After establishing that everything works as it should with the key manually (EKA coding, all doors respond to the turning key, no alarm messages) I concluded it must be the RF receiver. Just fitted a genuine LR replacement and still the car refuses to respond to buttons pressed on freshly manually synchronised fobs. Next I'm going to check power to the RF and continuity back to the BECM but any other bright ideas?
That's a bit of a bugger. Power to it comes from Fuse 15 but that supplies a load of other things including the tailgate lock actuator and the interior lights so you would probably know if that was blown (you would also get a message on the dash telling you it was blown). However, it does have a splice in the wiring where it splits to the different things so you could have a failed splice. This is from the ETM for a 97 model but it should, hopefully, be the same as yours.
PC38: back in #21 you were able to (temporarily ?!) resync. things with the usual 'fob button-press/luck-turn' sequence.... so there must have been power at the Rcvr. in order to do that (?). Or perhaps the power it is intermittent - ie. the plug-connector or cable is 'iffy' ? Thus the Rcvr. may well be getting power ok - but the signal not getting back to the BeCM ??
(You could only really investigate that at the BeCM with a 'scope - or you could try by just 'bridging' it with a wire of course)
I haven’t checked this on my P38, but on the Disco 2 I could tell on the Nanocom if the receiver was working (I needed to replace it).
Nano will also tell you if the p38 has received a valid signal, so a good place to start.
Dear All,
Thanks for the advice.
No the return of services after a lockout was immediate and for everything except for fob control. No evidence the RF is working. Unfortunately I don't have a Nanocom, only a Lynx. So its a continuity and voltage testing weekend. At least it'll be pretty quick to confirm suspected diagnosis, 12v + and - from battery terminals to RF and see what happens.
In my case on the Disco there was no problem with power or ground at the receiver. I needed a receiver.
PC38; Never quite that simple on a P38 of course but again this might help......
-and 'B'= eth. and 'OR' is the signal back to the BeCM
- but note this diagram is for a later car than yours (ie. with the "Passive Immobiliser Coil" on the Ign. switch)
Incidentally does the Lynx actually allow you to disable the (other) Immobiliser so you can just use the (physical) key ?
Dear All,
Re-kindling this thread because i've run out of ideas. As per previous posting out of the blue the car stopped responding to remote pressed buttons on the fob. Fob battery and LED all OK. She does respond fully and as expected with the key in the door. Keycode lockout, engine immobilised etc all work with the key in the door and when synch'd all four doors and interior lights work with the key in the door as they should. So my attention turned to the RF receiver. I bought a genuine new one. fitted it and nothing. I checked the power at the plug, a good continuous battery voltage and good clean connection to ground. Plugged it back in and the car then responds to the fob, as normal. locks and unlocks. I then try the key in the door lock, which again works as normal, but then it no longer responds to the buttons on the fob. Its almost as if its "forgetting" its synch via the RF.
Any ideas as to whats going on?
Dear All,
for info found the problem, i reasoned that the RF unit wasn't communicating with the BECM so checked the wiring and it was C236 at the BECM, connector was duff. Now all sorted and all working again. So I probably didn't need to buy the new RF after all - DOH.