Sterling immobiliser and battery

[JamesTiptree]

Good morning. Having extensively read the various BC threads about the Sterling immobiliser, including Jonathan's advice on fuses and resetting the system, I am still stumped.  A nice sunny drive yesterday afternoon was cancelled as my immobiliser wouldn't click off.

The issue is that the immobiliser (2022 Duratec) is not recognising the fob. Either fob in fact. What the immobiliser light does is flash slowly as it always did, but when the key is in the ignition and turned to position 2, it should flash faster as it looks for the fob. It doesn't, it continues slowly. The dials all do their normal sweep on turn of key.

I have checked every fuse (what a pain upside down in the passenger footwell!) and they look okay. I have called Scorpion whose only suggestion without seeing it (understandably) was that there might not be a live feed to the immobiliser unit, so to check the fuses. I wonder also if a flatter than normal battery might also mean not enough power detected by the immobiliser unit.

Other relevant things are that I have a battery master switch. Could I have somehow messed up the immobiliser by turning the switch somehow. Probably not. I have been using a new c-tek trickle charger recently and did so last night. Checked it this morning with the battery master switch off - 13.35v.  Checked it again with the master switch on and key turned to position 2 and it dropped to 12.47v and continued to drop as I watched it by 0.01v a second roughly.  I have in the past run out of battery and had to jump start the car and have had to top the acid levels up once.

I am hoping that by posting in this thread and as comprehensively as I can, it helps others in future.

I'm now at a point that I may buy a new Banner battery to see if that resolves the issue. After that, I may engage a car alarm specialist potentially. Any other suggestions very much welcomed, thank you! 

[Jonathan Kay]

44 minutes ago, JamesTiptree said:

...

I have been using a new c-tek trickle charger recently and did so last night. Checked it this morning with the battery master switch off - 13.35v.  Checked it again with the master switch on and key turned to position 2 and it dropped to 12.47v and continued to drop as I watched it by 0.01v a second roughly.  I have in the past run out of battery and had to jump start the car and have had to top the acid levels up once.

...

Before anything else I'd:

1 Check the fluid levels and top up if needed.

2 Charge on the smart charger and check that it completes the program.

3 Measure the battery voltage at rest, minimum during cranking, and at 3,000 rpm.

4 Charge on the alternator for at least 20 minutes.

5 Measure the battery voltage at rest, minimum during cranking, and at 3,000 rpm.

Jonathan

[Jonathan Kay]

45 minutes ago, JamesTiptree said:

...
I have checked every fuse (what a pain upside down in the passenger footwell!)...
...

You've done it now, but for the next victim... it's often possible to use the camera and screen of a smart 'phone...

Happy New Year (when this is fixed)

Jonathan

[ScottR400D]

1 minute ago, Jonathan Kay said:

Before anything else I'd:

1 Check the fluid levels and top up if needed.

2 Charge on the smart charger and check that it completes the program.

3 Measure the battery voltage at rest, minimum during cranking, and at 3,000 rpm.

4 Charge on the alternator.

3 Measure the battery voltage at rest, minimum during cranking, and at 3,000 rpm.

Jonathan

Good advice JK but if the immobiliser isn’t clearing, it’s probably not going to run at 3000rm, or crank. 😉

The battery does sound suspect though, it would be interesting to know what voltage it finally settled at. Having said that I’m not sure a failing battery would stop the immobiliser clearing. 
 

[JamesTiptree]

Left the master switch on all day so the immobiliser blinks as usual, without the ctek attached. Checked the battery voltage - 12.51 so that's where it settled Scott.

Jonathan thank you. I cannot turn the car over as the immobiliser won't disengage.  I've topped the battery up but it wasn't that low in any area.  The smart charger was on all last night and was at stage 7. I have set it back on just now and will check it's completed the charge tomorrow.

The answer to the question that I don't know is what level of voltage does the immobiliser unit need in order to begin it's search for the fob after turning the key in the ignition to setting 2. The Scorpion chap said that slow, normal blinking of the led could occur even if there wasn't any voltage to the immobiliser unit to react to the turning of the key to position 2, when the led blinks faster looking for the fob.

Another question I have - it's 13.35v when full charged it seems, but 12.51 after one turn of the key to position 2, where it remained. Is that correct?

Edited January 4 by JamesTiptree

[AlastairA]

James - a wild card suggestion - but yoiu don't use a USB charge point in the car do you?

I have one that incorporates an on/off button and voltage display. When the USB charge point is switched on, it emits sufficient Radio Frequency Interference to prevent the immobiliser from reading the key fob correctly. If the car is fitted with a USB charge point, disconnect it or switch it off and then try the immobiliser.

[Rich G]

If your Sterling installation is like mine then the switched ignition supply feeding the immobiliser is via Fuse F, so you could check for 12v there if you have a multimeter.  Fuse F also feeds the instruments etc, so is your fuel gauge working, or heater (for example). 

[JamesTiptree]

Two great responses, thank you. Alastair, good idea but no I don't. I have the Caterham 12v cigarette lighter and the trickle charger had been plugged into that so I did have a concern I'd fried something as I wonder if immobiliser was in some way connected to that.

Rich, good idea, I'll try that.  Weirdly when I looked, Fuse F wasn't a 5 amp but I think a 15. That said, all fuses were in tact. So you're saying I should be able to check the voltage at Fuse F? I'll try that. Yes my gauges all work but they might have enough voltage to do so and the immobiliser doesn't maybe.

[Andypscutt]

Just check the relays / sounds very similar to the issue I had / admittedly mine is a Sigma but the symptoms sounds much the same 

So swap the ign relay for another on the relay plate that is the same relay / don’t mix it up with the flasher relay 

[JamesTiptree]

Thanks Andy, I'll try that too. So literally remove another relay and use that to replace the ignition relay to test it (but don't use the flasher relay)?

[Rich G]

22 minutes ago, JamesTiptree said:

Weirdly when I looked, Fuse F wasn't a 5 amp but I think a 15.

Ah, so mine is definitely Fuse F (7.5A). There’s a second (plain black) wire from the fuse terminal with the white wire. That black one feeds the immobiliser. 
However, mine’s a 2015 Duratec SuperSport R and when I’ve looked at the wiring diagram at the back of the Assembly Guide for 420 it looks like the ‘instruments’ Fuse is ‘B’, and 10A. Maybe someone with your 420 wiring arrangement could could confirm that it’s Fuse B you need to be testing for 12V. 

[Andypscutt]

Yes James , mine had distorted at some point got hot and wasn’t making a connection , it sent me in a wrong direction as it manifested as a immobiliser fault so it’s worth a swap.

as long as the relay is the same type you can swap as a troubleshooting tool 

 

good luck I had this problem exactly a year ago and it was very frustrating 

[JamesTiptree]

Genuinely chuffed with the feedback that I've had in this thread, thank you. Plenty to be trying. Thanks most recently to Rich and Andy (Andy, the empathy is appreciated! I'm definitely too old to be upside down in footwells of cars!)

[Andypscutt]

😅 Yes - upside down and having to dislocate your upper body from the lower is no fun 

[JamesTiptree]

I have tried all fuses, checking for 12v each time. Everything that should be receiving 12v appears to be. Some aren't but it makes sense why they aren't, I think (cooking fan, for example)

The fuse for the instruments is receiving 12.15v. The fuse for the keyless immobiliser is receiving 12.35v.

I replaced a couple of relays. They look fine and replacing them didn't make a difference.

Some observations - removing the fuse for the 'keyless immobiliser' doesn't stop the immobiliser light flashing. My fuse board is not in line with the 420 manual. It took me a while to figure this, so my thanks to whoever at Caterham installed this. See photos below and you'll see they're in a different order, with a rogue 20 where there should be a 15 on the flasher unit fog/dipped beam. The battery read 13.8v after removing the ctek after an overnight charge, but the moment I turned the ignition key to position 2 it dropped to 12.3v and hovered around 12v.  

Tomorrow I'll try jump starting it off one of my other cars to give the battery full beans and will try to start it then. If that doesn't work I'll ring an alarm specialist.

Bottom line summary - immobiliser led flashes slowly as it does when the key isn't in the ignition or it's not disarmed. Then when turning the key in the ignition to position 2, the led doesn't flash rapidly like it's even looking for the teardrop fob (which makes me think the issue isn't that the immobiliser has lost the memory of the fob)

 

Edited January 5 by JamesTiptree

[Jonathan Kay]

10 minutes ago, JamesTiptree said:

...
My fuse board is not in line with the 420 manual. It took me a while to figure this, so my thanks to whoever at Caterham installed this. See photos below and you'll see they're in a different order, with a rogue 20 where there should be a 15 on the flasher unit fog/dipped beam.
...

Different layouts don't seem to be common on Duratecs, although there are at least three on Sigmas, one of which isn't in any known documentation.

I can't see any photos, but when you get them up I'll check the layout.

Jonathan

[JamesTiptree]

Yes, the photos would be helpful! Top one pinched from c7diaries and bottom one is a photo of my fuse and relay alignment.

Edited January 5 by JamesTiptree

[Jonathan Kay]

I'm sorry to perseverate over the system voltage, but we're using the car's battery as part of the diagnostic approach. And I once wasted weeks with a problem when the real cause was a CTEK smart charger that wasn't. 

I don't expect any electronics, including immobilisers, to drop out with 10.5 V or higher unless there are transients which don't show on an ordinary multimeter.

Something is causing the voltage to drop when you turn the switch. You can find out what that is by removing fuses in turn.

FWIU you can't now get the alternator to charge the battery. But you could check what happens when you connect the Seven to another battery or vehicle and try to de-immobilise and start, and of course measure the voltage while you're testing. 

Jonathan

[Jonathan Kay]

Thanks for the photo. Which of yours have you already identified?

Jonathan

[JamesTiptree]

I've identified them all now thanks, the blocks of three fuses were just in the wrong order, IYSWIM.

Using your logic that an immobiliser wouldn't fail to check for the fob if the voltage was over 10.5v (which it is, it just drops from 13.something to 12.something on ignition/key turn, which might be normal), then perhaps the battery isn't the issue.

The chap from Scorpion's view was the immobiliser unit might not be receiving power like it should be when the key is turned, hence the led continuing to flash slowly, not changing to fast. I wonder how, without taking all the wiring apart, I'd check the switched live to the immobiliser unit.

Again, normally at this point I'd have given in and called an alarm technician but given it's clearly a known Caterham problem, it made sense to play it out here. 

[Jonathan Kay]

Just now, JamesTiptree said:

I've identified them all now thanks, the blocks of three fuses were just in the wrong order, IYSWIM.

Thanks. Please can you list them... one day it will save someone a lot of time... 

Jonathan

[JamesTiptree]

5 minutes ago, Jonathan Kay said:

Thanks. Please can you list them... one day it will save someone a lot of time... 

Jonathan

Yes. As can be seen from the above two fuse photos (one from the manual and one of mine), the ignition relay, flasher relay and reverse light relay (and their corresponding fuses) are sat on top of the group of cooling fan, fuel pump and starter engine.

[AlastairA]

James - I wonder if it's worth trying to reprogramme your immobiliser fob?

There's a good video explaining the process by Callum at Turn 7 - watch from 5 minutes onwards : Link

[JamesTiptree]

Thanks Alastair. I'd seen and tried that but logically I don't think that's the issue. If one thinks about the sequence of events:

- battery master switch on

- immobiliser light flashes slowly 

- key in and turned to position 2

- immobiliser light flashes fast (indicating it's trying to detect the fob)

If I'm not getting to 'fast flash' phase, then the fob isn't the issue. That's how I'm thinking about this.

[JamesTiptree]

https://www.pistonheads.com/gassing/topic.asp?h=0&f=101&t=1367057 exactly the same issue here. Would add to the above that neither of my fobs works. I need to figure out why it won't go into detect mode when the ignition is switched.