Non-boaty: how can I test a car remote key thing?

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NealB

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Car is a Jaguar X series, 2001 vintage (yeah, glorified Mondeo).

I can't use the remote to unlock or switch off the alarm.

I've fitted a new battery, which has had no effect.

Is there an easy way to test the remote, please? It doesn't have any light, and the action is very 'indefinite' (not nice and clunky, like the one for Jos's Fiesta).

If it's not the battery for the remote, what other problems could there be?

At the moment, I can't use the bloody thing. I can get in with the key, but this sets the alarm off (annoying the neghbours), and the engine is demobbed.
 
Thanks, Jim.

Tried that.....no change!

It's very odd. It's worked reliably for years, and was working fine the day before I noticed that it had gone wrong.

Frustrating!
 
can you get the electronics out to test outside the key? It's a well known issue with old Vauxhall keys where the rubber wears and prevents the button being pushed. If you try this, make sure all of the key parts are together in case there is a code device in the rubber bit, and obviously make sure you reset the key first.
 
It is also worth opening the keyfob and using a cotton bud to gently clean the gold contacts under the rubber buttons and also the rubber contacts themselves. You can sometimes find the finest black residue which can actually stop the fob from working. Apparently you should use "de-natured alcohol", but a dab of vodka work just as well.
 
Thanks Jim and lusty.

I opened up with the key, and ignored the alarm, so that I could get the manual out the glove box. Having now (yes, belatedly) RTM, I realise I can switch off the alarm and demobiliser with key.

So the car is back in action.

Will do a bit more delving into the remote buttons.

Thanks again.
 
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As another 2001 X-Type owner I can confirm it's not infra red.

One of my keys won't lock the car. I suspect the contacts are a bit dirty as has been mentioned because the other buttons work.
 
Just had a thought - do any of the buttons work? If you can lock the car or turn on the headlights with the fob then the problem must relate to the unlock button.
 
NealB said:
None of the buttons work, so I'll try cleaning up the connections as a first step.
Click to expand...

I was heavily involved with problems with Jaguar cars back in the late 90's early 00's. Key fobs can be infra-red, wireless transmitters or induction loops, yours is probably wireless transmitter operating in-band between 433.050MHz and 434.790MHz

You will find that your key fob is a 433MHz transmitter and the problem might not be with the key fob but with the TRF broadband receiver fitted in the car.

If they have rolled out a TETRA transmitter within a ¼-mile of your location, the car sees this 'constantly on' digital signal coming from TETRA as an attempt to steel the car and will inhibit your car and not even 'look at' your key fob transmission. TETRA transmits just below and above the 433MHz band and the cheap receivers fitted by the motor trade are wide band receivers which will quite happily 'see' these TETRA transmissions.

This just might be your problem?



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johnlilley said:
One way to test any remote (or most infra red) is to point it into the lens of a digital camera, the camera can see the light.

John
Click to expand...

Perhaps years ago but these days almost all cameras have an IR filter on the sensor to prevent it mucking about with the image. One notable exception is the Canon EOS 60Da which specifically does not have one since it's for astronomy :)
 
Nice techy David, but the key worked faultlessly for years?


lenseman said:
I was heavily involved with problems with Jaguar cars back in the late 90's early 00's. Key fobs can be infra-red, wireless transmitters or induction loops, yours is probably wireless transmitter operating in-band between 433.050MHz and 434.790MHz

You will find that your key fob is a 433MHz transmitter and the problem might not be with the key fob but with the TRF broadband receiver fitted in the car.

If they have rolled out a TETRA transmitter within a ¼-mile of your location, the car sees this 'constantly on' digital signal coming from TETRA as an attempt to steel the car and will inhibit your car and not even 'look at' your key fob transmission. TETRA transmits just below and above the 433MHz band and the cheap receivers fitted by the motor trade are wide band receivers which will quite happily 'see' these TETRA transmissions.

This just might be your problem?



.
Click to expand...
 
nigelmercier said:
TETRA shouldn't affect the receiver at all, they are different frequencies. . . . . .
Click to expand...

You have just made the classic mistake that the manufacturers made when they installed the wireless electronic car locking devices and this is a very common problem when using cheap SRD's, Short Range Devices which include Car key fobs, garage door openers and wireless burglar alarm systems. Type Approval of electronic equipment does not now extend to testing compliance of the receiver stages of these systems, only the transmitters and manufacturers are penny pinching and use inferior systems which are often useless.

Yes, the TETRA transmitter frequency is 10 MHz or so below the transmit frequency and is a cleanly transmitted signal with no out of band spurious signals but a cheap TRF (Tuned Radio Frequency) receiver is a very wide band receiver with a wide open front end, if you can say a TRF Rx has a front end, and is capable of receiving signals 20 to 30MHz wide whereas the key fob transmitter only had a transmitted bandwidth of 10 kHz or so.

The Key fob receivers should have been based on a SAW (Surface Acoustic Wave) device or a superhet to make the receiver only capable of receiving a very narrow band FSK signal from the key fob transmitter. A TRF receiver centred on 433MHz is quite capable of receiving signals from somewhere about 420MHz to 445MHz and would clearly 'see' the TETRA signal.

You obviously did not read or understand my thread (#14) carefully enough. :(




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