Drivers Information Module (DIM) diy repair

[keithC70]

Recently, thanks to Budulan, I've managed to repair my faulty DIM from my '03 S80 D5 SE Auto, and took photos whilst I had it apart. I had the SRS warning, occasional loss of green indicator arrows, and jittering un-readable dim display.

I firstly disconnected the battery and left for a good while before starting.

To remove the dim on my car you firstly remove three screws from beneath the steering wheel housing and then carefully loosen the upper half. There are then two screws in the upper face of the dim surround. The two surrounds are connected and lift out together.

There are then four screws holding the dim in place and one multiplug to remove once it's out.

185 shows the rear face of the dim on which I've marked the 7 scews to remove with a black blob. You can then lift off the white plastic back.

You can see a further 8 screws each with a white marker square on the pcb. The pcb now lifts off as in 189, and turned over in 190. The chip with bad contacts is the one on the right with the blue varnish removed. I used acetone and cotton buds along each edge and on top of the chip to remove all the varnish.

198 shows the chip cleaned. I then simply worked my way along each side with a fine pointed soldering iron to re-set the joints. The first time I did it, I only did one side nearest the centre of the pcb and it cured some of the faults but not all.

The second time I did all four sides much more systematically so that I know every joint was re-made. I used liquid flux and repeatedly tinned the tip to maintain good contact and to keep the tip clean. This is very difficult to do as you need a powerful magnifying glass to see and a steady hand on the iron.

I then used self adhesive heat sinks as on 203 just in case overheating was the cause.

After 200 miles it's all working correctly.

I'm happy to help anyone with their dim - give me a ring on 01792 545880.

[jajrst]

I don't suppose you know what the SRS code that was stored was do you? Thanks very much for the info and pictures, it will be very helpful

[keithC70]

Yes - when I bought the car and started reading up about the faults I soon realised I wasn't going to resolve much without a code reader.

I bought the BSR one from Nordic and initially there were 21 fault codes stored, but all deleted and only 5 returned.

The relevant ones are DIM 0006, orange warning lamp, and SRS 00D4 SRS, indicator lamp.

The SRS warning and the light both disappeared after I soldered the side of the chip nearest the centre of the pcb at the first attempt, but the flickering readout and the missing green arrows made me take it out and do it again more thoroughly.

I couldn't detect any loose or bad connection by eye, so I don't know how many there were, or where, but the method certainly works.

Both the above fault codes deleted after re-fitting DIM and not recurring.

[chrisg147]

cool, thought this deserved more than an automatics 'thanks' so - er.. THANKS!!

[jajrst]

Ah cool, thanks for the info. I'm trying to diagnose an air bag error, well have been for the last year or so lol. Mines' to do with the passenger air bag though (I bought the BSR too, What a great bit of kit!) so it can't be related unfortunately/fortunately. I have always thought it was a bad SRS module but the other day when it was 27 degrees, I reset the ABS light (I was cleaning the sensor and the engine light and ABS set permanently, all gone now) and the SRS light reset too much to my surprise, fine yesterday too, now its cooled down today, its back with a vengeance and won't reset. Must be a solder joint somewhere... more fiddling required

[Be_happy]

Hello KeithC70,

I hope you can help me.
I have also a 00D4 error as you wrote you had in 2009. I have soldered I think almost everything on the PCB. You wrote that changing the bulb solved your problem. Do you remember which bulb you changed?

Thank you in advance.

Best regards,

Be_Happy

[D5meister]

Im guessing the reason for the unreliabilty is the use of lead-free solder.

When the eco warriors pushed for ROHS, factories making consumer electronics were forced into using lead free solders, fluxes and new pcb plating techniques.

The results were fairly poor, the solder needs higher temperatures to melt and the fluxes were new and more of a health risk to operators.

Lead free solder is hard and does not flow well. Original Tin/Lead solder with correct prep and fluxing runs like quick silver and sets like a mirror if correct and gives a very reilable long life connection.

Automotive producers enjoy a concession from ROHS which allows the use of leaded solders for reliability. It looks like volvo wanted to go greenand used a supplier who was not fully experienced in lead free.

If they mixed the processes this can give reliability issues, eg plating to take leaded - and mixing up the order and using lead free solder - which ive seen done at a CEM..

NASA will not use lead free as it does not give confidence in future reliability.

https://www.google.co.uk/search?q=ro...6rJoTXasT1g8gO

I have worked in a factory where the pcbs were plated with a gold flash to take lead free but the plating wasnt right and all of the parts could be flicked off with your nail.

This is Electroless immersion gold pcb plating was in its infancy when these pcbs were being made and you can get black pad which stops the solder wetting.
The gold is intended to creep away as the solder wets the pads leaving clean nickel alloy for the solder to stick to.

If one of these processes is a little out then solder does not stay attached forever.

If they tinned the pads using HASL finish the used lead free soldet this is bad too.

When you solder your pins be mindful that we shouldnt mix leaded and non leaded solders.
We dont know what they used for certain..

[hobbyhorse]

Originally Posted by keithC70

Recently, thanks to Budulan, I've managed to repair my faulty DIM from my '03 S80 D5 SE Auto, and took photos whilst I had it apart. I had the SRS warning, occasional loss of green indicator arrows, and jittering un-readable dim display.

I firstly disconnected the battery and left for a good while before starting.

To remove the dim on my car you firstly remove three screws from beneath the steering wheel housing and then carefully loosen the upper half. There are then two screws in the upper face of the dim surround. The two surrounds are connected and lift out together.

There are then four screws holding the dim in place and one multiplug to remove once it's out.

185 shows the rear face of the dim on which I've marked the 7 scews to remove with a black blob. You can then lift off the white plastic back.

You can see a further 8 screws each with a white marker square on the pcb. The pcb now lifts off as in 189, and turned over in 190. The chip with bad contacts is the one on the right with the blue varnish removed. I used acetone and cotton buds along each edge and on top of the chip to remove all the varnish.

198 shows the chip cleaned. I then simply worked my way along each side with a fine pointed soldering iron to re-set the joints. The first time I did it, I only did one side nearest the centre of the pcb and it cured some of the faults but not all.

The second time I did all four sides much more systematically so that I know every joint was re-made. I used liquid flux and repeatedly tinned the tip to maintain good contact and to keep the tip clean. This is very difficult to do as you need a powerful magnifying glass to see and a steady hand on the iron.

I then used self adhesive heat sinks as on 203 just in case overheating was the cause.

After 200 miles it's all working correctly.

I'm happy to help anyone with their dim - give me a ring on 01792
545880.

Well done Keith, top job done & thanks for posting the pics; I'm sure many here will find this thread useful

[keithC70]

Well since I re-worked my dim I've covered about 2000 miles and it's still working ok. The only small problem I have is that occasionally the green turn lights and the clicking sound don't work even though the indicator lights are working correctly.

Does anyone know specifically which joints on the pcb might cause this problem? If so I'll have another go, but it's not a major problem. It happens say once a week.

[keithC70]

Well I've had to take it out again and have another go.

The green indicator lights and click gradually got worse until they stopped working altogether, although the indicators all continued to work.

Also the orange warning triangle and SRS warning came back, and then finally the scrambled information screen. AAAAARRRRGGGHHHHH!!!!!

So I spent a good four hours at the weekend and carefully re-soldered every joint on the pcb that I could get at. Fitted it back ........ and the clock and temp screen didn't work.

Off again and eventually realised all that needed was a new bulb!

So back in again and now all back together and working correctly. I hope it lasts longer than the last time. I've only done about 500 miles since the last post.

This time I spent far longer on each of the joints and used more flux. I made absolutely sure that each joint was definitely melted. I was methodical and systematic. Last time I wasn't and may have missed a few or only partly did them.

Some of the adjacent connections on the chip were soldered together (because my iron's a bit too big and spans the contacts) and so I had to use solder extractor and make sure they were separate before I moved along to the next one.

I did nearly every joint on the board including the bigger ones that you'd think would be ok, so I'm now hoping that'll do the job.

I'll update again in about a year!