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2011 Subaru Legacy- Replace VDM?

Last week, the brake, traction control, cruise, and check engine lights all came on my dash. All but check engine were flashing. The car seemed to be driving fine but cruise would not engage. I drove it to a local mechanic who checked the battery and alternator and reset the computer. He said there was nothing wrong with the car. The next day the lights started flashing again so I made an appt to take it to another garage. This place said my gas cap needed to be replaced (hence the check engine light) and that my vehicle dynamic module was busted. The price they quoted to replace the VDM seems fair ($800). My dilemma is that since picking the car up 4 days ago, and driving roughly 200 miles since, the lights haven’t come back on. My current plan is to wait a bit and see if they do but I’m wondering if there’s a chance that the VDM is ok. Has anyone else had this experience?

This might be normal behavior for your Legacy when the check engine light illuminates. On my 08 Forester when the check engine light comes on the cruise control will not work and several other dashboard lights also come on. I don’t remember exactly because it’s been several years.

I would urge you to have the dealer or a local Subaru specialist look at it before you drop $800 on a repair that might not be necessary.

Good luck!

According to the subaru forum, any fault will cause all the lights you mentioned to come on. A loose gas cap will cause it. Don’t worry about the VDM.

On the Outbacks produced after the redesign of 2010, a loose gas cap (or any other problem that will cause the CEL to turn on) will result in a Christmas tree effect on the instrument panel. If all of the warning lights are now off, and if the cruise control is now working, the OP can safely assume that replacing the gas cap was all that was needed.

The mechanic who stated that the VDM needs to be replaced is either dishonest or is not as competent as he should be.

This is exactly what I was wondering, thanks for your comments.


I am experiencing the same problem as you.I have a 2012 Subaru Legacy. This has been going on since June of last year and we just get a run around from the service department (SD) at Reliable Subaru in Springfield MO. When we first brought it in, the SD said there were several CAN communication failure codes and they found battery failure codes also The battery was found to be ok though, they cleared the codes and drove it around and performed several ABS stops and found that to be working(the traction control light had come on) so they sent us on our way. About a month later the same thing happened, we went back to the SD and they said it might be due to a battery failure and if that was the case then the work would not be covered under warranty, We were given an extended warranty back in 2013 for 7 years and 100.000 miles because of numerous problems we had experienced since buying the car new. I took the car to a local mechanic who thought-as I did-that this was a grounding problem. He did replace some wires coming from the battery that seemed corroded and all was well for about a month. Then the problem came back. I took it in to the SD and they said it was the battery and it needed to be replaced at a a cost of over $300. I said no thanks but went out and bought another battery and put it in and only had to drive 20 miles before the same lights came on again. I was talking to a guy at the local Auto Zone who was extremely helpful to me and was very surprised that the SD just let it go at the battery. He indicated he worked for a few years at the SD. He said my most likely problem was a CAN failure due to an instrument control module failure. He said there are numerous instrument control modules on the Control Area Network that they communicate on with each other and if one of those fails, then our problem would occur.
I am extremely displeased with the SD in Springfield and also with Subaru in general. The SD should have worked on the CAN codes when they first came up last year but did not.They are just trying to avoid performiong expensive warranty work. I will never buy another Subaru again because of the experience I have had with this car and with the Dealer’s SD. I would urge everyone else to do the same.

By the way was your problem resolved?

"I drove it to a local mechanic who checked the battery and alternator and reset the computer. He said there was nothing wrong with the car."

A Subaru Technical Service Bulletin #06-41-11 (Oct/11/2011) Does Indicate That DTCs (Diagnostic Trouble Codes) C0074 and C0075 (Vehicle Dynamic Control) can be caused by low battery voltage that influences the ABS/VDC Pressure Sensor setting which can be lost.

I’d check (remove and clean, too) the battery cable connections for intermittent conductivity. Has the car ever been jump started?

Since 2011 cars were built between mid 2010 and mid 2011 the original battery would be 4-1/2 to 5-1/2 years old now. If you haven’t replaced the original battery it’s time to consider doing that.

Since the OP has not posted anything in this forum since she initiated this thread ~5 months ago, I think it is safe to assume that she is no longer monitoring this thread, and it is probably also safe to assume that her problem was rectified.

If you are saddled with a dealership that seems to be lacking either the ability or the inclination to help you with this problem, then you should escalate your concerns to Subaru of America. Contact info can be found in your Owner’s Manual.

In any event, CSA gave you some very good advice, and I hope that you heed it.

"The next day the lights started flashing again so I made an appt to take it to another garage. This place said my gas cap needed to be replaced (hence the check engine light) and that my vehicle dynamic module was busted."

Subaru Technical Service Bulletin # 11-126-12 (Nov/19/2012) explains that some owners of “later production 2011” Subarus are experiencing false “Check Engine” lights for DTC P0456 (EVAP Leak) and have attempted to remedy it by tightening the gas cap, but the problem remains. They have available a set of reprogramming files to update the car’s ECM (engine Control Module) and correct the situation.

Can you locate and read the Date of Mfg. on a label on the end of the driver’s door or door opening on the body to see when during the 2011 model-year this car was built? Also, a dealer can pull up the bulletin and using your VIN (Vehicle Identification Number) check to see if your car is eligible. I do not think this computer reflash is free, but shouldn’t be very costly.


VDC and Common sense,

Thanks for your responses. As I stated, I replace the battery got an optima red top. I did run the battery down and had to jump start it before buying the new battery. I also had a mechanic replace what appeared to be some corroded cables but there was also a clamp on the negative pole that I replaced that was not only broken but the wires were frayed at the connection to the clamp. Even after all this I have the dashboard warning lights coming on. I have also contacted subaru of america customer service and they will be coordinating with the local dealership to get my problem resolved. I am just extremely displeased that when this problemk first started they had found CAN codes on the diagnosrtic and didn’t follow up any of those.
So I am out $330 so far and the problem remains.

Common sense could I ask you: How many CAN codes are there for a 2012 subaru legacy? Is there a link you could provide on reading the CAN codes? What would the cost of replacing various defective ICM’s be? Could I do that myself? The guy I talked to at Auto Zone seemed to think fixing a CAN codes issue could only be done by a dealer, could a non dealer ASE certified mechanic fix the issue?

I am just sick and tired of dealing with the Subaru dealership and would rather have a local mechanic that I trust resolve the issue. Since I have replaced the battery and am getting the same warning lights, I think I’ll head to O’reilly and have them run the free diagnostics check to see what codes I’m getting now. I’ll let you know what I find out.

Again thank you very much for the prompt responses.

Just came back from O’reilly andf there were no codes that came up. Yet I still have a check engine light that stays on, a flashing brake light and cruise flashes,cruise control does not work,traction control light is also on.

@stevhoff Performing diagnostic procedures for module communication problems on a vehicle with a failing battery is a waste of time. So after three visits and seven months you replaced the battery, why not return to the service department for a proper diagnosis?

“Just came back from O’reilly andf there were no codes that came up. Yet I still have a check engine light that stays on, a flashing brake light and cruise flashes,cruise control does not work,traction control light is also on.”

In another post I mentioned C0074 and C0075 (Vehicle Dynamic Control) DTC (diagnostic trouble codes).

Some code scanners/readers cannot read “C” codes or “B” codes, but rather only “P” codes, like the P0456 that I mentioned in another post, the B, C, and P being the beginning of the code.

I Worked At A Couple Of Different Car Dealers (Not Subaru). They Were Fairly Large, High Volume Dealers.

Because the dealerships sold lots of cars and had lots of service work, they saw lots of car problems, often before smaller dealers saw particular problems, and sometimes before the manufacturer became aware of a particular problem trend.

What I would do is to list all the dealers within a reasonable distance. I’d call each one, starting with the biggest one, and speak directly with the Service Manager/Director and explain what’s going on, what’s been done, etcetera. Find out how long that person has been with Subaru. Then listen carefully when you ask for help and an idea of what’s going on. You should be able to tell which dealer can actually help you, which ones have the most experience, which ones are not helpful, and which ones are blowing smoke.

Make an appointment and go there. Some good dealers will accept a difficult challenge and some will even accommodate a person traveling a ways and let them wait while the car gets checked over. Some actually want to be better than other competition. Plan on spending some time.


Just a random guess but what about the possibility of a flaky transmission speed sensor?

“Just a random guess but what about the possibility of a flaky transmission speed sensor?”
Or a flaky wheel speed sensor… Seems to me I saw a bulletin pertaining to a wheel speed sensor wiring clip, but not necessarily in relation to setting a DTC and “Check Engine” light.

I doubt that working on this car over the WWW is going to be easier than a competent technician working through it, properly. They still exist, right?

CAN refers to the car’s computer network. That’s my diy’er guess anyway. There’s sort of a mini-internet inside cars these days, with a dozen or more computers communicating with each other over the CAN network protocol – the language that’s spoken on the CAN network; the dialog that goes on between the computers is generally a series of questions and answers among the various computers. If one computer asks a question and doesn’t get the expected answer, or no answer, from the other computer, that’s an indication of a CAN network problem and will generate a CAN code. If the CAN systems isn’t working, all the computers just throw up their hands as the CAN system has to be working for them to do their job. It’s like if the network cable becomes disconnected on your own computer, the computer pretty much goes bezerk, right? It’s helpless, has no clue. Same with your car. The problem is probably simple, but it needs human help.

It doesn’t matter if there’s one CAN code or two dozen. The key to resolving this is to locate a shop who has the proper scan tool for this vehicle, and a staff member who’s trained on how to use it. These kind of problems are pretty much impossible to figure out what’s wrong without access to those two things, the proper tool and a competent mechanic who knows how to use it. There’s just too much complexity to use the ‘try this, try that’ approach and expect good results.

Note the phrase above “proper scan tool”. That tool – really a computer in itself – might only be available at a dealership, and the closest dealership to you might not have it, or if they do have it, might not knowhow to use it. Frustrating, yes, but that’s just the way it is with newer cars.


“proper” aftermarket scan tools are available from any Snap On tool vendor . . . for example

OTC also has scan tools, but I don’t have any experience with them

In fact, anybody can buy the various factory scan tools, if they can pay for it

Clearly, no aftermarket scan tool can do every single thing the factory tool can do. But some of them are quite suitable for daily use. Many shops have a high quality aftermarket scan tool for general use, and a few factory scan tools for the more challenging jobs. Naturally, if a shop works primarily on GM vehicles, they’re not going to have the factory Subaru scan tool on hand.

Yes, a well recommended inde shop who specializes in subarus or at least Asian cars will almost certainly have the proper scan tool. It’s not an option. They have to, otherwise they can’t fix their customer’s cars. I think I’ve heard these referred to as Tech - 2 or something like that.