01 H6 VDC - ABS & VDC Lights On When Cold

[powderboy]

When the wind blows and the car gets extremely cold, both ABS and VDC lamps illuminate and I'm left w/o ABS and VDC just when it's needed most! I got to the top of a hill last Spring during a terrible snowstorm just to have the wind start blowing at the top and kick off my ABS/VDC in time for my descent. Needless to say it was scary as I ice skated down.

I'm guessing it's one ore more faulty speed sensors that are just sensitive to the cold. Any other thoughts?

Trouble is, I had a diagnostic this Summer (not from a Subaru dealer) and no codes came up. Since the lights only come on when it's really cold, I can't guarantee they will be on when I hit the dealership unless they can retrieve codes that other repair shops can't.

[plain OM]

I had a diagnostic this Summer (not from a Subaru dealer) and no codes came up. Since the lights only come on when it's really cold, I can't guarantee they will be on when I hit the dealership unless they can retrieve codes that other repair shops can't.

Yes, the dealer, using the Subaru Select Monitor, can access all OBD systems in the car that other code readers might not be able to read. Some repair shops might have readers that can do this as well, but they are expensive and therefore not as common. Common code readers can access and display mainly the engine/emission-related codes.

In most OBD systems there are provisions for diagnostic trouble codes (DTC) to be stored for some time (usually a predetermined number of drive cycles) after the original cause appears to disappear. However, I'm not familiar with what the ABS/VDC does in the 2001.

I would suggest that the next time the lights come on, try to get to a dealer as soon as possible. If the symptom is repeatable (i.e. on a cold windy day) that might be the time to visit, and have a tech drive with you. They can plug in the SSM and see what is happening at the moment.

[BOBOBW]

I have an 03 that does the same thing. Not just when it's cold though. Might go 2 months and not happen or might happen twice in a day. No good at the top of the hill but if I stop and turn off then restart the car it seems to reset it. Post back if you have the code read as I would be most interested. Seems only dealers have the equipment to read ABS codes. I have been told that ABS codes are stored just like the OBD codes.

[nipper]

My guess would be a wheel speed sensor, but i will look in my manuals tomorrow to see if there is some way to pull the codes.



nipper

[BOBOBW]

Nipper; I agree on the speed sensor thing. I also heard that dealers keep lots of tone rings in stock since they seem to be fragile

[nipper]

Originally posted by BOBOBW
Nipper; I agree on the speed sensor thing. I also heard that dealers keep lots of tone rings in stock since they seem to be fragile

Blu had his broken when a wheel bearing was replaced, so yes they are.

[driveby]

Originally posted by powderboy
I had a diagnostic this Summer (not from a Subaru dealer) and no codes came up. Since the lights only come on when it's really cold, I can't guarantee they will be on when I hit the dealership unless they can retrieve codes that other repair shops can't.

It sounds like your repair shop didn't know how to read ABS or VDC diagnostic codes. I bet they only read the engine codes with a generic OBD scanner.

I just read my codes last week for the first time. The ABS and VDC systems remember the last 3 codes that were thrown. It doesn't matter how long ago. My VDC light came on briefly about 3 years ago, battery has been disconnected a couple of times, and the codes are still in memory.

You can read them yourself like this:

1) Dive under the driver-side footwell and you will find a diagnostic connector (probably white) near the heater vent. Two terminated wires also come out of this bundle. They are probably black, and looped back into the tape unless your repair shop has removed them. Remove one of the terminated ends and plug it into the diagnostic connector like this: picture:



2) Turn your key so the dash lights come on.

3) The ABS light will flash the diagnostic codes. Pay attention! Each code is a series of long flashes (1.2s each) followed by a series of short flashes (0.3s each) followed by a 1.0s pause. Then the next code, etc, until all codes are shown. Then the sequence repeats. Count the numbers of flashes. The number of long flashes is the first digit of the diagnostic code. The number of short flashes is the second digit. The sequence always begins with a "start code" of 11 (one long flash, one short flash).

For example, when I hooked up the connector on my 2001 VDC and turned it on, the light flashed:

LSPLLLLLLLSSPLLLLLLLSP

where L = long flash, S = short flash, and P = 1 second pause. So, my codes were 11 (start), 72 (abnormal yaw rate sensor), 71 (abnormal steering rate sensor).

4) Post your codes here and someone can tell you what they mean...or buy a copy of the service manual and look them up yourself...or go to your dealer and ask them.

The dealer's tools provide even more information...but the basic codes might be enough to figure it out a DIY fix.

-Jeff

[driveby]

Almost forgot:

5) Remove the diagnostic terminal wire. I dunno if it is just a ground wire. If you have a second, check and let us know. Otherwise just tape it up again.

[jimarcor]

Hi All,

I have found that my '03 VDC is sensitive to tire pressure deviances. If my light comes on, more than once every 6 months or so, one or more tires is low by about 10 lbs. Keeping track of that keeps the VDC and ABS fully functional.

Hope this helps, Coach Jim

[gigapus]

This just happened to me this morning. It was -7 C, and I drove for about half an hour with the ABS and VDC lights lit. They never went out from the time I switched on the ignition, even before I even started moving. After I stopped I immediately restarted and they were gone. I have not checked the tire pressures yet, but I am sure that I would have noticed if a tire was as much as 10PSI low! I'll have to wait and see if it does it again, and try the diagnostic readout trick when I get a chance.