2001 T5 DSTC BCM ABS Volvo part 8634413

Post by **precopster** » Sat Nov 03, 2018 1:50 am

Just removed my 2001 T5 DSTC brake controller (ABS unit) and photographed the connector solder joints and the solder joints leading to the ABS pump.

They definitely need a touch-up.

I'm having DSTC Service Required, ABS brake failure and Brake System Failure especially on warmer days after the engine bay has accumulated some heat.

I used a 4mm 6 point socket to remove the studs holding the ABS controller in place.

I'll report in after it gets soldered and refitted.

Post by **abscate** » Sat Nov 03, 2018 4:36 am

Were those fasteners six point or Torx, Mike?

We actually sourced the Torx ones in SS here somewhere, I think.

Post by **precopster** » Sat Nov 03, 2018 6:29 am

I should have used E torx 5 as they were the standard ABS fasteners used on all Volvos. Matty Moo sent me the perfect E Torx 5 afew years ago which is on loan right now.

Here's how most of the joints look after desoldering and retouching them. The rough look is the flux that hasn't all been scraped away. These 2001 DSTC units don't have that rubber coating over the connector pins like the earlier units making it easier to rework them.

Post by **abscate** » Sat Nov 03, 2018 5:07 pm

Thanks for using the great searchable format for title, too.

Appreciated.

Post by **precopster** » Mon Nov 05, 2018 12:10 am

After 1.5hrs behind the wheel today (travelled to Geelong so mostly high speed freeway and tollway) a much better result with DSTC Service Required entertaining me on the dash display. It was quite a warm day though and the ABS Service Required message occurs mostly when stopped in traffic with minimal airflow under the Hoonett (hood and bonnet Anglo Americanised)

No Brake Sytem Failure or ABS Service Required.

A scan showed that the rear wheel sensor, front left wheel sensor and ABS Pump faults are gone for now.

Scanned and produced the following codes so the Yaw sensors in the cabin may have failed or require calibration. Very odd though that it now takes 1.5 hours to get a failure.

Post by **abscate** » Mon Nov 05, 2018 3:23 am

Screw PTR number for reference is 9203936

Joe pine hill sourced SS replacements from McMaster Carr in theP80 forum

We could send you some from here cheap if you can’t source easily

YouTube · Post by **oragex** » Mon Nov 05, 2018 5:12 am

Don't know about these modules, but the solder joints may not be the only weak point (we can clearly see them cracked in the zoomed in pic).

I brought my (infamous) 2003 DIM circuit board to a very nice tv shop repair, was asking them to reflow the chips on the board. The guy there was really great and told me he was actually going to check the whole board, not just the motorola chips (and took only $70 for the repair, sweet). Turns out several smd tiny resistors were also giving up after being powered for a while. Basically when these tiny resistors approach the end of life, they start failing after a few minutes/hours of power up, then come back again to life after resting (power off) for a while.

Post by **precopster** » Mon Nov 05, 2018 9:53 pm

Never heard of a resistor that "powers off" SMD is merely a surface mount pad on the base of the resistor or other device for attachment purposes.

It is more likely a need to reflow the solder pad under the SMD that has repairers confused; thinking that the device has failed, unless it's a CMOS device which is much more complex and will break down when faulty in a heated environment. It's easier in most cases to just replace the device than to clean it off and re-solder.

I'm not a big fan of re-flowing CMOS devices with an iron though as they are not heat tolerant, though a hot air blower under the board approaches similar temperatures as the production process. I wish I could hot air blow the entire board just to rule out breakdown of a CMOS device on this board.

I did the calibration of the DSTC unit today and will report back

Thanks for the offer of the studs Steve, will keep it in mind. As yet I haven't stripped any as I handle the boards after removal in most cases.

Post by **precopster** » Mon Mar 04, 2019 8:37 pm

XeModex don't handle these at all.

Vida shows the part number for my chassis as 8691265 up to chassis 170999

After that chassis the part number changes to 8671457

Post by **abscate** » Tue Mar 05, 2019 4:52 am

Hoonett (hood and bonnet Anglo Americanised)

Hoonett is now the official MVS name for the thing that goes over the motor that drives the tyres through the gearbox. It’s between the fenders, and in front of the windscreen.