2008 S80 AWD Automatic 3.2 T6-No revers lights

dnas501 · Post by **dnas501** » 21 Feb 2019, 20:21

Wondering if anyone has run across this situation.
The car is a 2008 S80 AWD with automatic trans and 3.2 T6 engine.
Trying to fix for my daughter S80, as she needs a state inspection in March 1, 2019
Reverse lights stopped working. All bulbs are good, all fuses are good. Can't figure out where the relay is or if there is one.
I have also replaced the Control on top of the transmission. (really difficult to do)
I saw info on "PNP" switch adjustment, but this vehicle switch is completely different than the pre 2008 models.
So no adjustments can be done.
Still no luck.I cant figure out where the signal for the reverse lights comes from.
I even checked the shift knob area. Does't seem to have anything in that area.
Thanks in advance for any input.

Post by **RickHaleParker** » 21 Feb 2019, 21:02

The part you have pictured is the TCM (Transmission Control Module).

The command for the reverse lights comes from the CEM (Central Electronic Module) located under the dash on passenger side.
The command from the CEM turns on relay K3 which is also on the CEM panel.
Relay K3 is powered through Fuses F11 on the CEM panel and (F1 (11A/1) Main fuse F2 (11A/2) Main fuse located under the hood).

Check the relay and the fuses.

Full HD picture, click to zoom.

dnas501 · Post by **dnas501** » 22 Feb 2019, 07:00

I did check all the fuse. They are all good.
I'm bot sure how to find out which wire actually goes to the reverse lights. To determine if the relay in the CEM is actually making. Also. Any chance you could RE send the image. I can't read much of it as its blurry. And thank you soo much for your advice/help.

Post by **jimmy57** » 22 Feb 2019, 07:27

Does the indicator in the tachometer showing "R" when in reverse? Does the LED by the gear lever for R light when in reverse?

Post by **RickHaleParker** » 22 Feb 2019, 07:35

dnas501 wrote: ↑22 Feb 2019, 07:00 Any chance you could RE send the image. I can't read much of it as its blurry. And thank you soo much for your advice/help.

Click on this to download the wiring Diagram.

Be patient that server can be a little pokey.

dnas501 · Post by **dnas501** » 22 Feb 2019, 08:07

Sorry I didn't answer this earlier. I'm new on this post.
Yes both light up when in R.
The one on the dash and the one on the gear shift.

dnas501 · Post by **dnas501** » 22 Feb 2019, 08:26

Are the CEM relays internal or external?
In other words are the relays replaceable as individual components?
Or does the whole CEM have to go and re-program etc.
Thank You

dnas501 · Post by **dnas501** » 22 Feb 2019, 08:30

Are the CEM relays internal or external?
In other words are the relays replaceable as individual components?
Or does the whole CEM have to go and re-program etc.
Thank You

dnas501 · Post by **dnas501** » 22 Feb 2019, 11:47

I'm trying to follow the wiring diagram.
Trying to see if the (mentioned) indicators are the same power as the lights. In other words if the relay output is OK. And it's the same source. That means I have a broken wire somewhere.
Thanks very much for your help.

Post by **jimmy57** » 22 Feb 2019, 13:44

The indicator on dash and on GSM being lit indicates TCM is delivering signal into network.
K3 relay soldered on CEM board is the relay. Fuse F11 on the CEM is the fuse. It is 4th counting from right on top row. Pull it out and inspect to make sure it is not loose contacts for that fuse. the connectors that are the fuse connections are soldered onto board and they can be stretched. Those piggyback tap connectors are notorious for stretching these board mounted fuse connections. There may have been something installed on the car at some time in the past. Make sure the fuse is good. The fuse is input to K3 relay. Power supply goes out on C2 pins 62 and 73. Unlikely that both have bad connectors and a loose C2 connector would kill other stuff also. 62 and 73 are on two different rows in C2 but are next to each other. That connector is not one that hinges onto connector, it is one with a handle and it pulls into connector pins all at once.