Hello all,

Volvo part # 1363569 (with a bunch of different names)
The one in my 1993 945T has a date 17-02-2009 so it's quit before.

The ABS idiot light is on, OBD port A-3 lights but no codes return.
No 1-1-1, nothing.
The FAQ and posts indicate the "Transient protector" and/or its resident 10 amp
ATC fuse can have failed. I checked the fuse and it's OK.

Can someone elaborate how to get the "relay" loose from where it's mounted?
Is there enough slack in it's harness to get a meter on it to test?

The posts say you can't get this "over-voltage protector" apart without
destroying it. Is that so? Has anyone tried to repair?
I'd cut the case off with a Dremel to see if a diode or resistor
went open.

It's interesting that the 1994 940 doesn't have this "circuit breaker" at
all. Do the 93 and 94 940 ABS controllers have different part numbers?
Maybe the solution is to get rid of the "relay" and jump +12V direct to
the ABS controller?
Where is the ABS controller located?
The pictorial shows it next to the "relay", but I didn't see it there.

Thanks, Bill

Sorry, don't know how it is used in a 9-series.





I suggested this workaround for someone who could not locate an affordable replacement.


--
Art Benstein near Baltimore

I had no Monet to buy Degas to make the Van Gogh.

Thanks Spook and Art, two Brickboard champs!

I finally got this critter out and there's a SPST relay and a resistor
and a BYZ50K22 Transient Voltage protector diode (press fit into a husky heat sink) It measures open in both directions.
Mouser has it for $3.15

https://www.mouser.com/ProductDetail/Diotec-Semiconductor/BYZ50K22?qs=OlC7AqGiEDl0NAr27G1lDw%3D%3D

Now Go to Scandix and see what they want for the relay 200+ EU
Plus a gigantic core charge .... Yikes!

Art this is across the 12V input to the ABS controller. Used up to 1993 in the 940, then 94 they dropped it - dunno if the 1994 ABS controller has a
voltage suppression diode instead of the external with the relay.

Or did Volvo just forget that diode altogether in 1994?

The 1993 940 pinout for 2/18 Transient protection relay:
pin 1 Battery +12V (this leg has the 10 amp ATC fuse)
pin 2 +12V to ABS controller pin 1
pin 3 Gnd
pin 4 +12V from ignition swich #151

Dunno if I want to replace the diode or jump 12V to the ABS module like they do in the 1994. It's fed off the ignition switch #151 and they use a spare fuse--F24 and it's a 15 amp and not a 10, direct to power that ABS module.
I don't know yet how much current the ABS module uses and certainly don't want
to blow up ignition switches with too much current.

Now to see if I can source a diode locally.

Art, does your website have a e-mail link, I'll send you the schematics

Bill

Replacing the diode requires de-soldering the links from the connector to the PCB and the diode, leaving the relay and resistor connections alone.
The old diode punched out OK but the aluminum section was easily distorted.
Getting the new one in was an adventure, and I'd search for professional
installation tools before doing this again.

Now I have +12V to the ABS module (pin 8, Y/R wire)

But still no ABS reporting at OBD A-3.

Does the ABS controller suffer from cold solder joints, or corroded connector pins, or have any known high mortality components? Where is it?

Which is the module directly under the Left side of the instrument cluster?

What is the small module way to the drivers side fender? This one
is a problem to reach.

There's the black box that the ABS relay is clipped to?

Are there any under dash 940 photos to ID the different modules?

None of the above look easy to remove.
Must the driver seat be removed to work under the steering side of the dash.

Do I need to hire a dwarf mechanic?

Thanks, Bill

Dear B.B.,

Hope you're well and stay so! It has been a while since I've been "under the dashboard". Starting from the left (closest to the driver's door) there's a rectangular, dark brown module (usually Part #9130207). This is about 3" (75mm) square. It manages the cruise control.

Moving to the right - towards the center console - there's a rack-type mounting, on which you'll find: (a) the ignition module (black, about 5" (125mm) square; (b) the ABS module (aluminum, about 3"x6"), usually with a pink label). Both of these are secured with screws.

I can't recall a post reporting ABS module failures. I'd guess they're little stressed, given mounting position (inside the cabin) and infrequency of use. That said, corrosion - that can disrupt a circuit - can occur, if a car lived in a sea-side or other high-humidity area.

Removing the driver's seat certainly eases under-dash access. Before removing the seat, be SURE to remove the negative battery cable clamp from the battery's terminal. Put the clamp into a plastic bag. This cuts power to the SRS system, the mondule for which is mounted on the floor pan, under the driver's seat.

While unlikely, a seat dropped on the SRS module could trigger the airbag. This will - at least - be very costly: the windshield is likely to be cracked and all SRS parts will have to be replaced.

After disconnecting the negative battery cable clamp, wait 10-15 minutes, to allow any SRS module capacitors to discharge.

Hope this helps.

Yours faithfully,

Spook

Dear B.B.

Hope you're well and stay so. The first thing to do is to this: disconnect the negative battery cable from the negative battery terminal (make a note of the radio's security code). Cutting power to the electrical system - waiting a few minutes, and then reconnecting - sometimes clears a fault light.

Second, the ABS controller is above the driver's footwell, under the instrument cluster. There's a mounting for the ABS controller and the ignition control module. The ABS controller is rectangular and has an aluminum-colored case, with a pink label. If I recall correctly, the controller is secured to the mounting frame with one or two screws. These controllers seem well-made. I don't recall a post reporting a failure.

The ABS Controller's part numbers are: Volvo# 9128853 / Bosch# 0265 101 031. There is an earlier iteration, with Volvo# 3523142 / Bosch# 0265 101 028. I've tested both iterations and each proved serviceable.

The relay's aluminum case is crimped to the plastic base on all four sides. The crimp is about 3/32" above the lower case edge. To remove the case, you'll need to cut through the aluminum case, along the crimp itself. I've never done this. I'd use a Dremel with an emery cutting disc. Little pressure should be needed.

The rely has a clip, that slides over the mounting frame for the ABS controller, if I recall correctly. You can wiggle the relay so that the clip disengages.

Hope this helps

Yours faithfully,

Spook