I have a 2002 v70 and the check stop light goes on when I hit the brakes. The brake light on the sides do not light up only the bar in the middle does. I checked the bulbs and both are good. Where do I look for the problem?

 

Make sure the bulbs are seated well in the socket. If they are also look at your 3rd brake ligh. Sometime the little bulbs go out and trigget that. Mine did eventhough the rest were fine. Also if a bulb is on its way out, it might trigger the light.

 

Check in the rear computer in the trunk. Is there any other things not working?

 

I checked the bulb seating and they are good. I also checked the brake pedal switch and that is ood too. What would you look for in the rear computer?

 

Fuse 11D/3 (most likely cause of problem) in the rear electronic module (REM), rear of car, left side OR
Relay 2/79 In the REM OR
Brake shunt component 20/31 in the REM

It looks like these components supply power to the left and right side brake bulbs only, not the top brake strip so this would explain why the top brake strip still works.

 

^^They have the best solution...


however for what it's worth, I have had brake lights, running lights, AND backup lights fail to light on both my V70 and my S80. I quick slap to the taillight housing has fixed it every time. I don't know what it is, but something gets loose once and a while and the bulbs fail to light.

If it's the shunt and not the fuse, it's a dealer part, they're $9 I believe. I've had my turn signal shunt fail in the past, and bought two and keep one in the glovebox just in case.

 

fuses are all good. Do you have a diagram of the REM to locate the shunt and the relay? I can't seem to match the numbers you list.

 

In the rear cargo area, behind the left (driver) side removable panel, you'll find the REM. the shunts are the wide black ones. Swap out the brake light one with another on the panel and see if it fixes the problem. If it does, you have a bad shunt. You need part # 9442190. I've attached a screenshot from Vadis showing the shunt, and where they go.

 

I swapped out all the shunts and it did not solve the problem. I guess it must be the relay. Is there anything else to check?

 

I would check the relay next.

 

Is there any way to check it electrically or should I just buy a new one and swap it out?

 

Swap it out with another one in the fuse box.

 

Turned out to be the relay. Just as a note there was a recall on the relay and the original one was replaced by two separate ones on Recall campaign no. 131. Just Google v70 brake light relay.