Mondeo (III) Radio Code Question

Shouldn't be doing it is all I can say. It's nothing to do with the options.

Did you get the exact right type of battery fitted? I have heard of bizarre faults on some late Fords if a standard battery is fitted, usually solved by replacing with the proper type.

It should say "silver calcium" on the top of the battery. (this goes with the smart charge system fitted to later Mondeos)

Nothing to do with the battery. The code is kept in an eeprom. You'll probably find this is faulty.

Chris

Serious question - if it is in an eeprom, why do people seem to lose it when the battery is disconnected?

An internal memory chip in the radio

derrrr. To make it uselss if nicked.

Thank you. That wasn't really what I was questioning. I was wondering what leap of logic lead you to believe that a faulty component in the radio was more likely to cause the OP's problem than an intermittent loss of the permanent feed? Especially as the fault only happened after a battery change...

Chris

No - maybe you misunderstand my question - an eeprom holds ins contents without any power. So battery or not will not affect it.

The EEPROM does not loose its contents; the security software in the radio detects the removal of the permanent 12v feed and goes into code prompt mode as soon as you apply power again. People only seem to loose the code because it's in the document pack that never gets passed on from previous owners!

Ok - I can see two ways of doing this

1. The radio detects loss of power and asks for a code and compares it with eeprom contents once only after input. The input code is not stored.
2. The input code is stored in RAM and the radio checks the contents of the RAM against the EEPROM on every switch-on.

In case 1, the EEPROM could theoretically "fail" and no one would notice until such time as power was lost and input code requested. In case 2, an EEPROM fault would cause the comparison to fail and the code would be requested at switch-on.

In either case if the EEPROM remained faulty it would not be possible to input a matching code.

It was a heavier duty battery. The original battery (4 years old) was ok when the engine started immediately. In those situations where the engine had run for a few minutes and switched off, the restart took longer running of the starter motor, and the strain showed. I had a flat battery after leaving sidelights on overnight, and called Homestart before putting the battery on slow charge. AA arrived within 15 minutes and a test of the battery showed it pretty poor, so I opted for replacement.

It's just an occasional irritation to have to re-set the code...

Will check in daylight. :-)

In message , Geo writes

All very interesting, but the loss of code is still basically a symptom of power loss. I will note the frequency of occurrence in case it happens on Friday 13th or something. :-)

It's a real pain when it does it on a busy road. No music, Sally Traffic or Sat Nav until I can stop to reset it.

But was it a silver calcium battery, as has been required for Fords of the last decade or so?

Chris

I can see no indication that it is a S/C battery.

There is no marking on my Focus to indicate that either. Nonetheless, if it's a post-2000 or thereabouts Ford, that's would it will have had.

Chris

But the fact that it accepts the code when it is entered means that the PROM/flash is fine. An intermittent break or short on the live feed is the most likely explanation. If it tends to happen when you hit potholes, I'd check the areas where the cabling passes through the bulkhead and clips. If it is completely random, or happens after a particular duration I'd look for areas which could be near a heat source. Intermittent faults are always a pain in the rear to track down...