Another Turn Signal Issue

[Dezz]

New member. With a similar issue.

I just bought a 2007 XC90. Being 12 years old, it has some issues that I am slowly fixing up.

The problem that has me right now is the turn signals. The right turn signals do not work.
If I put the stalk in right turn signal position then pull the stalk to flash high beam, the turn signals will work for as long as I keep the flash high beam on (does not work if I click the stalk to high beam).

I have opened up the stalk and cleaned the circuit board contacts. No change.
I even built up the contact point with solder. No change.
I replaced the stalk with a known good used one. No change. Even cleaned the contact points on this one. No change.

Flashers work perfect. Left turn signal and all other options on the stalk work fine.

Last week the right turn signals worked for about 1 day. And they worked perfect for that day. It was raining that day, so it was wet. I wonder if that has anything to do with it.

I have read that the hazard lights use the same relays and inputs to the CEM as the signals, but do they use the same wire contacts?

I have no idea where to look next with this.

Edit: it is raining today, but the right turn signal is not working. Maybe last week was a fluke.

[ggleavitt]

Right side turn signals work only when stalk is pulled back, is this still a replicable scenario?

Does the headlight switch position make any difference as to whether the right turn signals work or not when stalk is pulled back?

[Dezz]

Right side turn signals work only when stalk is pulled back, is this still a replicable scenario?

Does the headlight switch position make any difference as to whether the right turn signals work or not when stalk is pulled back?

Yes it is replicable at any time. It is the only way I can use my right turn signals at the moment. And it only activates lane change mode with 3 flashes.

The headlight switch does nothing. I turn the dial but nothing changes. Lights on all the time.

[ggleavitt]

Thanks for reiterating the scenario- Left signal works fine, right signal only "short cycle" and only when stalk is pulled back as the lever is switched.

One more question- do both sides of the emergency lights work properly when the red triangle is pressed??

The turn signal stalk interfaces to the SWM, an active module which sends data commands to CEM which turns on (and off) the lights themselves. CEM as well provides a signal to the DIM for the instrument panel indicators.

It seems like you're been able to demonstrate that the light assemblies themselves work fine when they work so I'll assume the CEM is functioning properly for the time being. If both side hazards work then it's even more likely that the cause is not the CEM.

My "guess" is an issue with your steering wheel module (SWM), maybe on the board or the module is not interfacing properly with the CEM (code corrupt or LIN bus connection issue). If you can get a Volvo centric code reader connected to this vehicle you "should" note an error code which would help identify more closely where the issue lies. As a side note, SWM is behind the SAS contact reel, it's the circuit board that the stalks connect to.

VIDA has a good amount of information on function, and there are a few comments in the troubleshooting section for NOT arbitrarily identifying CEM as the cause until all other sources have been investigated.

[Dezz]

Thanks with that kind of information.

All the signal lights work fine when the hazard lights are turned on.

I have been suspecting the circuit board behind the steering wheel. That's the area I'll concentrate on next. Work my way down the line.

[Dezz]

Figured I'd close this thread off right.

As of right now, I have the turn signals working.
I removed the turn signal stalk, and visually inspected what I could see of the circuit board of the steering wheel module. I noticed the 3 bottoms pins of the green connector had cold solder joints. At least they did not look like very good solder joints. Using a soldering iron, I re-flowed the solder on those 3 pins. I also cleaned the circuit board using contact cleaner and an acid brush. This did remove some of the blue anti-corrosive coating, but it had to be cleaned anyway. There was no other choice. You can re-apply something if you like. I left it like it was.

Put everything back together and now everything works like it should. Hopefully it stays working.