2004 XC70 Instrument Cluster Issues

Post by **BlackBart** » 22 Mar 2022, 13:13

My '04 XC wagon with 140k miles has some instrument quirks that have recently changed.

From when we bought it used with under 130k, the digital clock just spins and spins. Sometimes it returns to normal after a half hour or random time, but then it will start spinning again. At one point, I tried to just press on the reset pin and it would either slow way down or even stop. But it wouldn't stay.

Issue 1 - no clock, no outside temp gauge, which is extremely handy.

In an earlier repair, I replaced the fuel pump and pickup / sender. As you know, the hoses and electrical connections snake from the left tank to the right. I think I somehow got the hose tangled in the fuel sender arm, so the dash gauge will only go from almost full to just over half. When It warms up enough to work outside and I have a Saturday, I'll take it out and see what's wrong.

The reason that's a significant story is that I just use the trip odometer to judge tankfuls and range. Works fine. Just have to pay attention and reset the odd at gas fill-ups.

Recently, the trip odo has decided to reset itself in a completely random way. I hear a tiny beep, wonder what's up, and later discover that was the odometer resetting itself to zero. Sometimes right after you drive off, sometimes later, sometime once a block...beep...back to zero.

Issue 2 - Randomly non functioning trip odometers - can't tell how much gas we have left. (so that's two fixes I realize)

So first task is to find a cluster removal DIY (I thought I saw that it comes straight out, without lifting the dash top like in a P80). Is that correct?

Would I find a loose connection or pin or ground nut back there? What would I be looking for? What would cause these maybe unconnected quirks? Is the DIM a closed box with dark magic inside and no way to diagnose? The clock feels like a connection or mechanical issue.

Post by **BlackBart** » 22 Mar 2022, 13:44

Here's a simple removal -

In an old thread I read to never unplug this cluster without the battery disconnected - true?

More info - My information screen works fine, all the warning lights, the tach and speedo, temp, etc. It's just the digital clock and the trip odometers.

This shows the guts. He's using a micro-soldering iron. Is that fine wire he uses the solder or the flux?

Another...

Post by **BlackBart** » 24 Mar 2022, 10:12

So the DIM itself is just one of these little square IC's on the board?

Are they implying there's likely nothing wrong with it, it's just cracked solder joints on the board? Is this common, that a modern electronic circuit board would fall apart like that? Is it flexing? Vibration?

I'd be nervous about soldering to those tiny little traces on the board without it running across and shorting. You must need a high quality, very small tip iron.

02V70 · Post by **02V70** » 24 Mar 2022, 13:59

My dash is also F'ed (so bad that nothing works), and I will be attempting the repairs in shown in the video relatively soon. I will let you know how it goes.

The DIM itself is everything in there. The square ICs are the "brains" of it.

Yes, in the videos, the problem is that there are cracked/bad solder joints. It is likely you have the same problem too. It is not that common that a modern electronic circuit board will fail like this. However, it is common that the Volvo dash circuit board fails like this. I think it is due to vibration, and poor manufacturing.

It is fine if the soldering iron touches multiple pins when you are soldering, as long as the hardened solder does not contact multiple pins, and the unit is unplugged. As there is a capacitor in the DIM, it may be a good idea to drain/short it before soldering.

Post by **jonesg** » 24 Mar 2022, 15:28

There's a YouTube video showing how to reflow everything at the same time by placing the circuit board, solder side down , on a household iron.

These instrument panel problems seem to come in clusters...
Duh.

02V70 · Post by **02V70** » 24 Mar 2022, 15:42

Can you find the video? I looked, but had no luck.

Post by **BlackBart** » 24 Mar 2022, 17:28

jonesg wrote: ↑24 Mar 2022, 15:28 These instrument panel problems seem to come in clusters...

HA!

Post by **br0dy519** » 24 Mar 2022, 17:38

Xemodex fixed mine. I find them absurdly overpriced but they do good work, and had no issues for the past 5 years. Lifetime warranty. Black friday often sees 15% discounts if you can wait till that time of year.

There is someone else in Toronto called "ModuleExpert" whom other users have vouched for as doing similar work. I imagine it's a former Xemodex employee doing the same services for a fraction of the cost. I would try them for my second car if my DIM decides to go. I cannot justify putting $500CDN into an instrument cluster.

Post by **Blacklab467** » 25 Mar 2022, 14:12

I used Zemodex for mine and they did a good job but $500 or so. Recently the clock and temperature window quit working so I'll have to get it back to them soon and get that fixed. It's not the bulbs....I checked. Let me know if you try the solder or iron trick with success. I might give that a try.
Also FYI, if you do decide to send it out for repair you can drive the car without the DIM.

Post by **jonesg** » 25 Mar 2022, 20:36

02V70 wrote: ↑24 Mar 2022, 15:42 Can you find the video? I looked, but had no luck.

There's more than one iron video.

I think it can be done much simpler than this by using an infra red thermometer gun $25 amazon to monitor the temp instead of building a digital circuit.

It's just a matter of getting the right temp for the time duration needed.

Read the comment section under the video. One guy used an old pan on the stove and had success. Maybe it was an elec stove.

Try with a scrap circuit board first.