About 2 months ago we started to see various messages show up on the message center. They appear once and then not again for several days. These messages include:

brake assist service required
coolant low, stop engine
engine service required
brake failure stopsafely

This '05XC90 continues to operate and perform properly. The coolant is NOT low, and the brakes are fine.Initially it was only the brake assist service message and I figured it might be the sensor or the ring that the assist monitors on one of the wheels caked with mud.We live on a dirt road, lots of mud this time of year. That has not made a difference, and now the other messages pop up.

I am starting to think its the computer (ecm? something else?). Is this feasible? If so, can I buy one online and install it myself? I hear they go upwards of $1,500 at the dealer. I haven't worked in a year and can't afford that hit right now. Any thoughts?

(Note, I haven't bothered to have any codes checked, assuming they would only say what the message console already has indicated, or amI wrong on this? I would go to someplace like AutoZone to have the codes checked, FWIW).

Or would a simple reflashing of the software be any help?

bmb

 

Sorry to say but you should really have all the codes pulled.

Autozone can only to the ECU but not the brakes.

I would also check all battery connections and ground connections.
Also check Alt. output.

 

Thanks. I'll have my wife leave the XC90 home on Wednesday. I can go through and check the battery and ground connections then.

How do I check the alternator output? I have a Voltmeter and an electrical tech background (from many years ago) but not sure of the steps to check the alternator.

I can have the codes pulled at Autozone or one of the others (Murray's, Advance Auto, etc.). Short of going to the dealer is there another place that someone can recommend where I can get these codes read?


Also, to add to the list, I just remembered there was a low battery message as well on one occasion only about two weeks ago. All electrical / electronic systems seem fine however.

 

Just ground the ground lead from the meter and put the positive lead right on the stud on the alternator and see what he voltage output is. It should be atleast 14.25 coming out of it.

I wonder of the regulator is going bad. What will happen at times is when it is cold it will charge good but the more it warms up the less it charges.