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Rear differential warning light flickers

Greetings.



I have a 2006 AWD Subaru Tribeca with 42,000 miles on it.



Recently my rear differential warning light has been flickering. This seems to happen when I give it gas and am going up a hill at maybe 50 mph or so.



I checked the owner’s manual which referred to hot differential oil or to the fact that the tires might not match. The vehicle’s snow tires were recently put on and do match. My under/over tire inflation light is not on.



Any ideas out there? I’ve been hoping that this is just some kind of computer or sensor screw-up, that is, that it is giving out false positives.

Can you get a sample of the fluid and smell it to tell if it really is overheating?

Wouldn’t the worst be that you have a overheating problem and ignore it?

Maybe a full on fluid replacement?

I want to congratulate you for reading the Owner’s Manual, which far too few people ever do. However, you have to go one step further, and read the other booklet that was provided, titled “Maintenance and Warranty” booklet–or something to that effect–for details on your Powertrain Warranty.

The Powertrain Warranty on my '02 Subaru was in effect for 5 years/60,000 miles, and it covered the differential(s), as well as all internal engine and transmission parts. I assume that your newer Subaru has coverage at least as good as what was provided in 2002, so you should be able to have this problem taken care of free-of-charge–as long as you have maintained the Tribeca according to the manufacturer’s maintenance schedule.

So, rather than dicking around with it yourself, I suggest that you take it to the dealership for free repairs. Even if you are told that “no problem was found”, having it documented on a repair invoice will give you coverage for differential failure even after the Powertrain Warranty has expired.

Don’t even attempt to give the service department a diagnosis, because they are required to go through a standardized diagnostic protocol, and they will likely ignore a diagnosis that you provide. Just state the nature of the problem in full and let them do their thing.

Incidentally, you have additional warranties besides the Powertrain Warranty, and the now-expired Bumper-to-Bumper Warranty. While you are at it, read the details of your Emissions Warranty, your Rust Perforation Warranty, and your Seatbelt Warranty. You just might be able to save some money in the future on other systems, just as I saved you money today on your differential problem.

That makes sense.

If they find anything, I’ll try to remember to post it here.

The tires need to match not only in size/model/type but also in tread depth. Are both tires the same wear(eg you did not replace one due to an unrepairable flat?)

You’re welcome.

Dealership checked it today, will replace the sensor once part arrives. Nothing wrong with actual power train. Job covered by warranty.

Famous last words. I hope they are last words and not famous words. It would be best.

OK news and good news.

OK news is they are replacing the sensor. That may well be it, but I’d guess that is only the first thing they do and if that does not work, they will need to go to step two.

The good news is they are going to foot the bill and it is no longer your problem, other than making sure they get the problem fixed. Keep everything done in writing until you are totally sure they have it fixed.