This issue has been happening for the past year or so and I’ve sent it to a radio specialist (generic because no Jaguar dealerships where I am) and nobody has been able to figure it out. Whenever I change the volume, either through the knob or the buttons on the steering, the radio cuts out. If I keep on playing around with the volume it comes back at some point but might cut out again randomly while driving. It also cuts out or cuts back in if I change channels. Whenever it cuts out the ST/TP disappears from the screen. Till now, I’ve changed the volume IC and turned off the AF, but that has had no effect. Can anyone please explain what I can do to fix or diagnose it?

 

First, and not trying to be mean or anything...but it is a site requirement to introduce yourself here.. https://www.jaguarforums.com/forum/n...-intro-must-5/ ...also, please put your vehicle info in your signature and also where your at. NA Jags have different setups than EURO or AUS Jags....example NA has 4.0L only X308 and EURO/AUS has 3.2 plus fuel conversion options (propane etc..). That's why we ask for such info...appreciate it.

So, to your inquiry, ...rheostat...that's exactly where I'd be looking and it's common. Other than that, also check cold solder joints. Any standard electronics shop should be able to handle this, the radio's are all over 20 yrs old and tech has passed these girls by decades ago.

 

There is an AF (or ALTERNATE FREQUENCY) setup mode that can be selected by pressing 'TAPE EJECT' and 'AM/FM' simultaneously.
The display will show SETUP.
Select preset 8.
Toggle AF ON or AF OFF. (select OFF)

This might solve your issue?
Some selections will require the RADIO CODE so be careful what modes you change!!!!!!!!!!!!!!!!!!!!!!!!!
We were required to perform the radio head unit setup during new car PDI when I worked at the dealer.

All this setup is described in the ICE (In Car Entertainment) section of the OWNER'S literature booklet.(the one NOBODY READS)

 

i am curious what that procedure actually changes.

 

As far as I'm aware some markets use a different range of FM frequencies, due to their licencing laws. I know Japan does, compared to the UK. No idea how US radio compares to UK.

 

US FM stations are only at frequencies having odd decimals like 95.1, 95.3, 95.5 etc. ; UK FM stations can be at frequencies having both, odd and even, decimals like 95.1, 95.2, 95.3, 95.4 etc.

 

Jag radios, like most other modern radios, do not have a "rheostat" (potentiometer) for volume control but use a rotary "encoder" and a "volume IC" instead. "XJHater" has taken a correct action to first try with replacing the volume IC (usually MAX5440) but, obviously, the problem is elsewhere.

 

In the UK our national FM radio stations operate on multiple frequencies depending on your location. BBC Radio 2, for example, operates between 88 and 91mhz. AF uses RDS (Radio Data System) to identify the best frequency for a given station and automatically switches to it as you drive around the country. Before AF, you were constantly retuning.

I had an XJS HE back in '82 which had a Philips radio that tried to do this in the days before RDS. You would manually programme each preset with all the frequencies for its channel and the radio would choose the right one as you drove around.

Inevitably, the radio used volatile memory so you had to reprogram every time you disconnected the battery or (more likely) it went flat. If I recall correctly, I used to programme 6 frequencies for
each of the four national stations!

No idea which other countries used this system but my own experience is that it added no value in US.

 

The US does not use AF so I always disabled it during PDI.

 

I do appreciate

 

Well...thank you...that response clears that up.

 

Hello all, sorry for the lack of introduction. I have a 2001 XJ8 3.2L UK. 1 of only 3 XJ8s in my country so pretty rare. I am a bit of a novice regarding car-related terms, so please bear with me. The cold solder joints seem to be fine. Replacing the volume IC did not change much. I also turned off the AF option but no luck. Anyone got any other suggestions? The radio worked perfectly fine when I got the car a decade ago. This problem started occurring 3 years ago and I haven't seemed to get to the root cause of it. The antenna motor stopped working in the middle too so the antenna wouldn't rise up. I thought maybe those two were correlated, but after fixing the motor the issue has not been resolved (although before the radio didn't capture all the channels but since fixing the antenna that works now). Drastic measures would now be to import another radio head but I am leaving that as the last possible option.

 

I also wanted to mention it doesn't only cut out when I change the volume. That is one of the causes. Sometimes it will cut out on its own while its working when I am driving and then I can bring it back by either fiddling around with the volume or it randomly cuts back in on its own.

 

One possibility is that the "Mute" function of your radio is playing-up by itself. As I recently sold my car, I cannot check now but I remember that there were "telephone Mute" buttons on the radio and on the steering wheel controls. Perhaps you should check the setting of the "telephone Mute" function in your radio (see page 16 of the attached manual) and, if set to "ON", try with setting it to "OFF". Also, you may try with pressing these mute (telephone symbol) buttons repeatedly when your radio cuts-out just to see if it makes any change.

 

As these ladies age, the wiring contacts often become corroded, thus inhibiting
the proper flow to that circuit. Before you take the plunge for a new head unit, I
would inspect and clean all the circuitry that is radio related.

 

So turns out, despite saying so, my radio guy did not replace the volume IC but instead only replaced the variable resistor. Are you sure the MAX5440 would be applicable to my model and, if so, is it simply a plug and play replacement? And, lastly, any idea where I can source the 5440 from?

 

MAX5440 is a commonly used volume control microchip but the Jag radio may not have this very IC. Your radio guy should be able to identify the volume IC in the radio (the IC to which the rotary encoder, the part that he replaced, is connected) and get a replacement. If it is MAX5440, this IC is available from a number of online electronic components suppliers (you can google for it). Practically no microchips these days are plug and play but soldered to the PC board.