Weird electrical problem - 2004 XC90 T6 - high beams, parking lights, etc Topic is solved

Jrsimp78 · Post by **Jrsimp78** » 29 Apr 2017, 11:39

Hi all,

My 2003/2004 xc90 t6 has devloped a very strange electrical gremlin. The engine starts and runs fine and most things work however, the following is occurring

-Back lighting for all of the dash not working (including the message readout etc and the Center console.
-All dials work ok as well as messages but difficult to read due to no back light.
-the direction indicators don't work (hazard warning works ok)
-Front screen wash not working ( wipers ok)
-rear screen wash and wipe not working
-diagnostic (eobd) socket is providing no power to the reader.
-parking lights not working though when the ignition is on / engine running the dipped head lights and park lights are all on and can't be switched off ( the warning led on the light switch is off always.
-high beam headlights not working

Everything else seems to work ok including 12v out put interior courtesy lights.

So far I have check every known fuse and relay. ( under bonnet , end of dash , on the REM and on the CEM. (Relays tested for resistance across the coil.)
I have opened the CEM to confirm no obvious burn outs.

Unusually , the problem isn't intermittent , it's permenentl as described.

Any ideas ?

One point to add is that the car is currently laid up. I was just running it up and pumping up the tyres with a compressor plugged into the 12v supply. This continues to work fine. This is however when the problem presented its self.

I look forward to any response

Post by **cn90** » 29 Apr 2017, 14:17

The symptoms are suggestive of bad electrical ignition switch (located on the LEFT side of steering column).

Volvo PN is 8650054, about $55 at Volvo dealer. Do not use aftermarket junk, stick to Volvo OEM only.
Youtube has a few videos on how to replace it.
Very very simply procedure with Torx keys.

Whatever you do, do NOT accidentally remove the 2 halves of the WIRE CONNECTOR, if you do, you will have to look for wiring diagram to put it back together.

PS: Please report back the outcome...

Jrsimp78 · Post by **Jrsimp78** » 30 Apr 2017, 00:27

Hi , thanks for the guidance , seems to make good sense. I will go digging an report back

Post by **cn90** » 30 Apr 2017, 10:00

The average life of the ignition switch is about 120K-150K.
Just get a new ignition switch from Volvo dealer.

Below is a DIY ignition switch for 1999 V70, but the procedure is almost identical for the XC90.
- See the photo #4, note the BLACK cover on the connector, do NOT pry the Black cover open, wires will come loose and you will regret.
- Photo #5 shows the proper way to d/c the connector (leaving the Black cover alone).

Anyway, if you follow that DIY, you will be fine. Please report back if this solved your problems.

viewtopic.php?f=1&t=55868

Post by **cuhfs** » 30 Apr 2017, 19:08

Dumb question - Did you make sure the battery is fully charged? weak / Uncharged batteries are known to cause gremlins.

Jrsimp78 · Post by **Jrsimp78** » 02 May 2017, 05:10

Hi all. Update ,
I'm assuming that the battery is ok as there are no issues with starting.
I haven't replaced the ignition switch but I have tested it. It seems to be fine. I removed the white cover and checked each contact by pressing the "cam followers" no signs of wear etc.

Any other thoughts?? My. Next check is for wild life living in the bulkhead section of the wiring loom.

Jrsimp78 · Post by **Jrsimp78** » 02 May 2017, 11:53

Hi All,

A slightly embarrassing discovery/solution.
Having checked every fuse an relay taken most of the removable dashboard panels off , pulled out the DIM, stripped the CEM down to PCB level, dismantled, tested and reassembled the ignition switch. Checked wiring diagrams from all angles......... I then checked the owners hand book. Yes, the one that is stored in the glove box, checked under fuses and happened to notice the description;

"22. Headlight switch module, climate control system, onboard diagnostic connector, steering wheel lever modules 5Amp"

I was positive that I had checked every sing fuse but I guess that's life.

Now I need to solve the other rough idle/ low power problem. Symptomatic of a leaking intake manifold gasket.
With this, the said gasket was leaking. I successfully replaced and it ran so well that I even got a phone call from the wife when she was driving it to say how amazing it felt. This status lasted 3 days. Then back to the same lumpy idle etc etc. No visible evidence of intake leak ( tried pressurizing via the break boost port and plugging the inlet pipe to the charge cooler then spraying soapy water on the manifold but only from the top side / ends. Also need to check the etc gasket..

Thanks for your help and guidance.
Every day's a school day.

Post by **scot850** » 02 May 2017, 14:35

What ETM does this use? Volvo had an issue with ETM contacts but I thought mainly up to 2002 when I think they were made by Magna Merelli (?) in Italy. Not sure what is fitted to the 03 XC90 T6?

Neil.

Jrsimp78 · Post by **Jrsimp78** » 02 May 2017, 15:46

Hi , I think it's either a bosch or VDO. As you mentioned , I don't think the xc90 ever suffered from this issue.
One interesting thing is that on the Eobd the throttle never opens more than 85%. I think volvo may have reprogrammed to give the gearbox more of a chance. (After a new box was fitted under warranty.)

traudesa · Post by **traudesa** » 02 May 2017, 17:37

Try pulling the two vacuum hoses attached to the intake manifold, plug them up with your fingers, and see if the idle improves. If it does, you can assume a vacuum leak on one of them (it wouldn't surprise me, there's plenty of places a leak could develop). I'd also hook up a scanner and take a look at things like fuel trim to see if anything stands out; you may find a good clue or two. Lastly, try the glove test and see if your PCV is clogged up.