Question about traction control 95' Legacy L AWD

[Bushwick]

While diagnosing an issue with the oil light, I had the cluster out and was shining my flashlight through the holes for the bulbs to see what was what. I noticed there were several empty slots for air ride suspension high, etc. while most others were just blanks. BUT, the TCS had bulbs in it. One is apparently for when the wheels spin, the other is a TCS failure check light. Thing is, I've yet to see either of them come on with key ON? Would expect the TCS failure/trouble light to least illuminate with key ON. And considering both slots had actual bulbs in them, I'm thinking the car has traction control. Anyway to be sure if it's a feature or not? I have some sort of aluminum block on the railing just in front of the filter box with what appears to brake lines entering/exiting it. Is that for the TCS?  

[Gloyale]

While diagnosing an issue with the oil light, I had the cluster out and was shining my flashlight through the holes for the bulbs to see what was what. I noticed there were several empty slots for air ride suspension high, etc. while most others were just blanks. BUT, the TCS had bulbs in it. One is apparently for when the wheels spin, the other is a TCS failure check light. Thing is, I've yet to see either of them come on with key ON? Would expect the TCS failure/trouble light to least illuminate with key ON. And considering both slots had actual bulbs in them, I'm thinking the car has traction control. Anyway to be sure if it's a feature or not? I have some sort of aluminum block on the railing just in front of the filter box with what appears to brake lines entering/exiting it. Is that for the TCS?  

 

That box with the brake lines is ABS not Traction control.

 

Traction control was not offered on any USDM models that I'm aware of.  Not sure why there would be bulbs in there......sure it wasn't empty holders?

[Bushwick]

Yeah, I'm sure they were not empty holders. They both contained bulbs and had copper circuits for contacts. The Ride Height too High was an empty green slot which had no copper on the circuit board. 

 

The one TCS light has "TCS" then several ~~~ marks (on top of one another) indicating slippage and was I think yellow; the TCS warning light was just "TCS" IIRC and I think the same color.

 

-What physical clues in the engine compartment could give me a definitive yes or no if the car has it or not? (maybe a shared fuse?)

 

-Do either of these lights typically flash with key ON in later models?

 

-What is the earliest year TCS was a known option (Legacy or Outback)?

 

-You know, one thing that's struck me odd about the car is the steering wheel has basically no wear or smoothing, and same goes for the auto shifter. Other than scratches here and there from careless PO, I'd swear the cabin area was a 40-60k mile car. Only thing that really looks out of place is the grey carpet. Everything works which is surprising considering it's showing 178k miles. Point is, I'm wondering if cluster is original or not as that could be a reason why it'd have bulbs.

 

Not a fan of TCS, especially on a low hp car, but if it does somehow have it, it'd be a nice option to blurt out at a future buyer. Once I get the sway bar link repaired, I'll go find a gravel road and see if it warns when slipping or not if it can't be determined beforehand.

[Bushwick]

Spent some time researching online and digging through the owner's manual. Apparently TCS was an option for this year, but purportedly only offered in FWD vehicles, though technically the manual doesn't implicitly state that. The manual does however state "If equipped" and mentions it ONLY affects the front drive wheels. Another oddity is there is NO actual fuse for the TCS, so I'm wondering if it's shared with the ABS?

 

Since I have the "AWD ABS" sticker in the hatch glass which I believe is because it was still an option then, I'm thinking this was actually going to be or was a FWD car that was converted after the fact, hence still having both lights. If that's the case, I'm wondering what might happen if I added a TCS switch to the plug? (going out on a limb here, but I'm going to say the TCS switch plug is behind the dummy cover) Would be interesting if it's deactivated/activated with the switch removed, and/or needs to be in forced FWD with the fuse inserted.

 

Anyone actually look into this? 

[WoodsWagon]

The TCS uses the ABS module and pump/valve body assembly to do its job, but they are a different ABS unit built special to be compatible with TCS.

 

Light bulbs are cheap, so it's much more likely that the holes in the cluster were filled with them so the same cluster could go in a car with TCS or without and not cause any issues.

 

AWD did not come with TCS.

[Bushwick]

AWD did not come with TCS.

 

Right, I got that. Since AWD was an "option" though in 95, I'm wondering if the car started life as a FWD variant and was converted to AWD as a dealership deal or something. There are no bulbs for the air suspension holes, but the bulbs and holders are still there for TCS which was a FWD option. 2 bulbs and holders might not cost much on their own, but multiplied times hundred thousand cars or so; it'd be purely wasteful on Subaru's part. But if the car was intended to be a FWD car with that option, then it'd be installed. The circuit board is there for them as well, but not the air ride lights. If they were being wasteful, all the instrument back-light options would be filled with bulbs, holders, and have copper circuit contacts for them.

 

I'm hoping someone can pinpoint what's actually different with the ABS between the FWD with TCS and my AWD. I'm wondering if they just deactivated the TCS feature (leaving the ABS stuff alone) while only adding the AWD parts to the conversion. 

 

It's more of a fun curiosity than anything else. Just thinking it'd be neat if it could be reactivated easily while running forced FWD or keeping the AWD engaged. Might make really slick roads less treacherous. I'll investigate behind the dummy panel and see if the connector is indeed there for the switch. Then see if it still has power or needs a relay, and try jumping to see if it does anything.  

[WoodsWagon]

No dealer would have converted a FWD Legacy to an AWD one. It's not an easily installed option, like say floor mats.

Subaru was "wasteful" in a lot of ways. All legacy wagons have the wiring for the rear wiper motor, equipped or not. Same with rear door speakers and the tweeter wiring. They just used the same main harness regardless of the trim package.

 

Air suspension wasn't available as a USDM option 95+ so there'd be no reason for any bulbs in those positions. TCS was, so populating those two bulb positions meant that they only needed one part # cluster that would cover all those cars.

[Bushwick]

Who would have done the AWD conversion then if it was just an option? On a hoist with people that know what they are doing, I'm guessing it could be knocked out rather quickly in a modular fashion. Might not be as simple as say dealership installed standalone AC on an early 80's Rabbit, but optional either means it was installed from the factory as-is and sat on a lot until sold, or it was added to a lesser model by someone after it was requested or based on demand.

 

Wiring harnesses are like that in pretty much all cars. I know Ford, Lincoln, Chrysler, GM, and Saab did it off hand. Often the plug for switches are already installed, or the main harness has the plug socket that will accept the switch harness as it's easier to incorporate, this way they don't have to waste time keeping track of which vehicles are capable of carrying what feature. In those situations, I don't believe it's "wasteful" as it's saving them $$ and time in the long run as they are no longer limited to a set number of vehicles only being able to accept certain features. It also streamlines the entire process as they can add virtually any feature at will to any chassis. Some bare bones factory cars don't get that treatment though. i.e. manual windows, locks and 2 speaker "FM radio" in a "work" van typically won't have the harness for power windows or locks, and no wiring for rear speakers, etc.

 

Anyways, if somebody knows what differentiates a TCS ABS unit from others as well as if there are separate modules and relays for the TCS in FWD cars, please speak up as I'm interested in learning about it.