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Full Guard in message box

(1999 Volvo S80)
in Saint Marys, GA on January 22, 2011
It started with an occasional ABS warning light. Unplug battery, and restart. May work 2 weeks, or 2 min. Then I got this Full Guard message?
Displaying 1 answers & 2 comments
Popular Answer
This car is old enough that I suspect the ABC electronic control unit is beginning to fail. Unplugging the battery resets the light but the E.C.U. has a memory of events, and after a certain number of times, it has decided the problem is serious. A Volvo scan tool is the next step. Good luck, cheers, Andy in SF
on May 05, 2011
Exactly, in January I finally found a complete service manuel. After some traceing I found the CEM was defective. Additionally the sirem module had failed. After replacing the siren module, the Fully Guarded message was gone, the ignition would operate position 1,2,3, but when it got to position three it would not pulse the starter.
replaced the CEM, but it requires a visit to a Volvo shop.

Oddly, before this event the Fresh recirculate would toggle every few hours. After a CEM replacement this is no longer an issue. But I lost the odometer and Cruise light (message). crazy electronics. cruise still works, and the service light comes on every 5,000 miles. thanks for the response. I hope this helps some other S80 owners/ technicians. Steve Schmidt
on May 08, 2011
Hello Steve,

Interesting situation.

So to recap:
- siren failed and has been replaced
- the CEM failed and has been replaced
- light for cruise control not working
- odometer not working

What I’m thinking:
1. Install new overload protection relay

Is it possible that a faulty siren damaged the CEM? No way to be sure, of course.
In our shop we recently had in a 2004 S60 with a “soft” code (no check engine light) for a faulty overload protection relay. I advised the customer to replaced the relay as inexpensive preventive maintenance. ( the relay won’t fix anything, but makes it less likely other parts will go bad)

2. Return trip to the shop that did the work
a) the service light interval is programmable, and it may be their shop policy to set it to 5K miles

b) try and get them to troubleshoot the cruise control light and odometer as part of work that was done the first visit ( if your homeowner’s insurance could get involve, they refer to this sort of 2nd visit as ‘hidden damage’

Hope this helps,

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