HELP! - ABS, TCS on - Power Sliding Door opening and closing


1999montana
11-19-2014, 09:39 AM
BTW, why is the forum asking me to register when I'm already logged in?


Before anyone asks, it's a '99 Montana EWB.

OK, I know I have an issue with clean water entering the cabin and depositing itself in the channel next to the driver's side rocker where a fair number of wires are located. It filled with water last fall and I dried it out and never thought too much more about it, but knew there was water coming in somewhere. At first I thought it was the AC, but the drain is clear and running.

It's similar to the damned TSB Bulletin No.: 01-08-45-005E that is a sticky here on the forum.

This time however, I didn't check for water in the fall and this morning in a blinding snow storm at 14F the power sliding door acted up 5 minutes before my wife left for work. By the time she got to work the damned TCS and ABS idiot lights came on, and she says the sliding door attempted to open, but she got it to close.

Now the van is 20 miles away and I won't be able to look at it until I can get it home and try to dry it out again. In the driveway in a snow storm!!! Grrrr.

If GM had been a little more specific about the root cause of water issues mentioned in the TSB, it would make life and fixing this problem that much easier.

Tech II, do you have any suggestions? Am I just grasping at straws hoping to dry the damned thing out now?

Anyone?

1999montana
11-20-2014, 09:19 AM
Part 2:

Rescued the van from my wfe yesterday afternoon and brought it home to start analysing the problem with the PSD and TCS / ABS.

When I started the van there were no lights on, the PSD was locked and nothing seemed out of place. I drove it home. Everything worked as it should.

Pulled the step plate off both sides when I got it home and rolled the carpet back. No water anywhere on either side. A little frost moisture as I would expect for -8C outside, but no evdence of standing water. Kept a couple of 1200 Watt heaters going in the van for about two hours which made everything toasty warm.

Since we have had a real cold snap this week, (parts of outlying Buffalo got hammered with 6 feet of snow BTW) I can only attribute what happened to ice lodging in the courtesy/door ajar switch at the rear of the PSD and perhaps some stray current that found its way into the wire bundle under the mat leading from the right side rocker channel to the BCM module.

If that is what happened, then finding the root cause would take more effort and a nice warm garage for a day or two to fix. The other remote and very unlikely possibility is 'negative energy'; - meaning my wife has this way of drawing on negative energy that causes inanimate objects to stop working. It's like voodoo or something, I kid you not!:headshake

She's been in a blue funk lately and maybe the van doesn't appreciate her driving it. Who knows!

Tech II
11-21-2014, 02:18 PM
Unfortunately, you need a scan tool to read ABS codes(ABS problem will turn on trac light)....now, if the code is set for the rear wheel speed sensors, then I would look at the pass through connection, located behind the driver's seat, under the body....disconnect and look for corrosion on both halves.....if the code is from the front speed sensor(s), then you have either a harness or hub problem....but you need the code to point you in the right direction....

As for the PS doors, if an intermittent problem, first place I look at are the "finger contacts" in the door where they make contact with the plate in the pillar.....they can get corroded/dirty.....I use steel wool or crocus cloth....

1999montana
11-21-2014, 06:29 PM
Unfortunately, you need a scan tool to read ABS codes(ABS problem will turn on trac light)....now, if the code is set for the rear wheel speed sensors, then I would look at the pass through connection, located behind the driver's seat, under the body....disconnect and look for corrosion on both halves.....if the code is from the front speed sensor(s), then you have either a harness or hub problem....but you need the code to point you in the right direction....

As for the PS doors, if an intermittent problem, first place I look at are the "finger contacts" in the door where they make contact with the plate in the pillar.....they can get corroded/dirty.....I use steel wool or crocus cloth....

All good points, and I will look into the pass-thru connection and harness points when I can get it in our garage on cement (long story, no time!). I'll guess that since it triggered the TCS/ABS on the dash that the code is still stored. Will talk to our shop and see what the scanner pulls out and get back to the board. The PSD is all original as far as I can remember. Never had any work done to it except the replacement of the interior door handles on a recall. Have had to reset the PSD using the procedure GM lists once or twice.

I wipe the fingers down periodically along with the contact pad in the 'B' pillar from time to time. Didn't want to get too agressive with it when cleaning, but will try some light abrasive on both the next time I can get my hands on the van for more than an hour.

I must say it had me spooked when two seemingly unrelated sub systems started acting up simultaneously. The van has about 269,000 Kms on it now and doesn't owe us anything.

I keep the maintenance up to keep it 99% complete and operational because I still have one kid in University and it makes the best hauler we have ever owned. Even with major repairs it still warrants spending the money over buying a new, or newer vehicle; - as long as replacement parts continue to be available.

1999montana
12-04-2014, 10:05 AM
Still haven't had a chance to get the scanner on it to see what caused the ABS / TCS to throw a code. Seems to be running OK.

1999montana
02-07-2015, 09:33 AM
Problem seems to have resolved itself. Was really cold here when I posted and ice was building up between the doors and body. Probably had something to do with the PSD acting up.

As for TCS, no issues at present. Wiring channels on either side of the van (under the carpet) were dry and free of moisture. Found the splice/repair the dealership did for the issue I had with power door locks about 13 years ago. Looks like they did a good job of repairing it.

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