XC90 keeps blowing fuse 11 (ECM, SRS, etc)

ritchiehicks · Post by **ritchiehicks** » 25 Jul 2018, 03:09

Hi,

I'm hoping that someone can help with an intermittent, difficult problem to pinpoint.

Last week, XC90 broke down whilst driving. All the dash went (everything including A/C, radio) and some other circuits. Checked fuses with multi-meter. Traced to and replaced fuse 11 (7.5A) and the car was fine.

A week later, fuse 11 blows again. Replaced it but kept on blowing. Pulled all relays under the bonnet, replaced the fuse, kept on blowing. Called RAC - couldn't fix it - recovered to garage 4 hours later.

Garage put a few fuses in this morning, and after a few popped, it eventually started.

So, this is an intermittent problem, which is going to be almost impossible to trace if it's not blowing fuses. Also made more complicated by the fact that a number of systems run off of this circuit.

I've checked basic wiring that I can see, no obvious signs of chaffing. Seems to be worse when very hot, could just be a coincidence.

Does anyone have any advice on where to start looking? I totally appreciate it's hard to diagnose a fault that isn't there all the time!

Thanks in anticipation.

Post by **RickHaleParker** » 25 Jul 2018, 05:45

Traced to and replaced fuse 11 (7.5A) and the car was fine.

That would be F11 in the passenger compartment. It is for:

Switch, passenger side airbag
Supplemental Restraint System Module (SRS)
Central Electronic Module (CEM)
Rear Electronic Module (REM)
Antenna ring/ignition switch illumination

This does not tell you where the problem is but it can save you time by not looking where it is not.

Post by **SuperHerman** » 25 Jul 2018, 10:29

Check the related relays and shunts in the CEM.

RickHaleParker is the wiring master - maybe he can tell you which one to focus on.

Post by **RickHaleParker** » 25 Jul 2018, 15:05

With intermittents, the biblical method is your best hope, seek and thou shall find. Wiggle wires and try induce the problem, visually inspect connectors and wiring. Of course seeking is all for nothing if you don't know what you are looking for ... you won't recognize it when you find it..

sailorbob74133 · Post by **sailorbob74133** » 23 Sep 2022, 01:22

I'm having the same / similar problem with fuse 11 popping. 2010 XC90 3.2L dual fuel with LPG conversion.

Car died while driving. Lost dash lights, but other electrical worked fine. Checked fuses and saw a 25amp fuse in the 7.5amp fuse 11 slot for the ignition. Apparantly placed there by previous owner or his mechanic. I replaced with a 7.5amp fuse and when turning the key to the run position it pops immediately. Replaced with a 30amp just to test what happened and could turn to run position, but then in start position it also popped. I hear something, maybe like a relay closing in the back of the vehicle when the fuse pops.

Here is the power supply wiring diagram I have:

: power_supply_ignition.png (262.8 KiB) Viewed 1692 times

Not sure where to start looking and wondering if the OP solved his problem...