2007 v70 2.5t brake lights not working

[Driven]

The bulbs are good on the left and right side, the center light is lighting up on braking, I was wondering if it is a brake light switch? If so not sure where it is located? Thoughts?

[DGM]

I don't think it is the brake light switch otherwise the third light wouldn't work (10/19). It means that the REM is receiving signal from the CEM when brake is applied (3/9). Beginning with the 2005 model, Volvo has introduced a new REM configuration for their V70. It is now transistorized. Gone are the relays, shunts & fuses for the brake lights. It is all internal now . I found this to show the new configuration.

Here is a few things to look at. Make sure you have the right bulbs. Check if one isn't creating a short circuit when inserted in its holder. Also verify that you receive battery voltage (yellow wire) when brake is applied (bulbs disconnected). If not, the problem is in the wiring or the REM. As an example the yellow wire can be grounded somewhere or if you have a trailer interface it can be defective. From there if you find nothing I would suggest to have the car scanned for codes with Vida-Dice.

In last resort if the REM is proven defective send it to Xemodex on a repair & return arrangement. This is much less expensive than installing a new unit.

http://xemodex.ca/technologyimproved/pr ... volvo-v70/

Hopes this help,

[Driven]

Thanks, I do have trailer interface, also I have a intermittent problem with one socket on right tail light. I know you have to replace entire light to fix, i have purchased new socket, but only worked for short time. Light bulb socket seems to get loose and bulb went out, reach in give it a twist it came on and then both sides went out!

[DGM]

If you need to remove/replace the tail light the following may help.

http://www.justanswer.com/volvo/672um-v ... -2002.html

[jimmy57]

The third brake light is operated differently. It is from REM but there is a direct wire from CEM for third light.
Has battery reset been tried?
Is there a brake light out message on DIM?

The REM can shut down circuits with faults and not blow a fuse. Sometimes the REM will not reset without fault code clearing or a battery reset.

[QuirkySwede]

The bulbs are good on the left and right side, the center light is lighting up on braking, I was wondering if it is a brake light switch? If so not sure where it is located? Thoughts?

What bulbs are in there currently? Please be specific.

[DGM]

The third brake light is operated differently. It is from REM but there is a direct wire from CEM for third light.

Just a point of clarification. The brake lights and third light share the same wire for input signal from the CEM (A15 to A18 in the wiring diagram above). However the REM has two distinct circuits for lights operation.

Brake light.gif (37.12 KiB) Viewed 6079 times

"The stop lamps (10/43, 10/50) are activated when the brake switch is (3/9) closed. A directly connected signal is transmitted via the central electronic module (CEM) (4/56) to the rear electronic module (REM) (4/58) and activates the relay. The lamps are powered via the relay. The central electronic module (CEM) transmits the data via the Controller area network (CAN) to the rear electronic module (REM) indicating that the stop lamp switch is activated. The rear electronic module (REM) sends status information for the lamp fault via the Control area network (CAN) to the central electronic module (CEM). In the event of a fault, the central electronic module (CEM) transmits data via the Control area network (CAN) to the driver information module (DIM) (5/1) which displays a text message."

High level stop lamp.gif (22.7 KiB) Viewed 6079 times

" When the stop lamp switch (3/9) is closed, a signal is transmitted to the central electronic module (CEM) (4/56). The signal is transmitted from the central electronic module (CEM) to the rear electronic module (REM) (4/58) via a directly connected cable. The high mounted stop lamp is supplied with power directly from the rear electronic module (REM). The stop lamp is supplied with power for as long as the stop lamp switch is closed."

[mirinex]

Hello to all. I have a 2007 S60 that just started giving mw issues with the brake lights. Every time when i start the car and person the brake pedal all lights come on and right away the left and right tail lights go out and i get a massage on the dash to check stop lamp. I did scan with an Autotell scanner and there is one code in CEM 8D01. If i erase it and then test the brakes they come on and same thing happens followed by the same code? Do you think it might be the CEM?

[Krons]

I had similar issue on 2002 S60 and was brake light relay in trunk of car.

[mirinex]

I wish i had relay in the REM, after 2005 there are NO relays in the trunk for brake lights.