Reverse lights do not work

Good day all.
My reverse lights does not work at all (both of them) as well as rear view camera. Bulbs are ok.
When I shift to R, display shows “R”, side mirrors are tilting to preselected position, so I think Shift Lever selector is OK.
Could not find separate fuses for reverse lights to check them.

Any idea what could it be else? (9-4x, 3.0, FWD)

Thanks in advance!

Well, diagnostics shows error: BCM can't see backup lamps. So it may be wiring problem from BCM to lams, or BCM is defective.

Have few questions about it:

1) when replacing BCM on SAAB 9-4x 3.0 FWD, does it need to be programmed or configured or something else other than "Plug And Play"?


2) Is BCM from SAAB 9-5 2.0t, 2010/11 identical for my SAAB 9-4x?


Thanks in advance!

Quote:

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Originally Posted by Saabaka

Good day all.
My reverse lights does not work at all (both of them) as well as rear view camera. Bulbs are ok.
When I shift to R, display shows “R”, side mirrors are tilting to preselected position, so I think Shift Lever selector is OK.
Could not find separate fuses for reverse lights to check them.

Any idea what could it be else? (9-4x, 3.0, FWD)

Thanks in advance!

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The Saab 9-4 is basically a Cadillac SRX with Saab skin and badging. This link brings you to an older SRX, but it does come with pictures http://www.fixya.com/cars/t10976565-...ac_srx_back_up

After some additional diagnostics, problem was found in BCM (Body Control Module). Wiring, bulbs and relays are ok.

Computer processes the signal and commands the module to apply voltage to the lamps.

BCM applies voltage to backup lamps for a very short time and then turns voltage off.
There is no short circuit after BCM, problem is inside BCM.

Quote:

---

Originally Posted by Saabaka

Well, diagnostics shows error: BCM can't see backup lamps. So it may be wiring problem from BCM to lams, or BCM is defective.

Have few questions about it:

1) when replacing BCM on SAAB 9-4x 3.0 FWD, does it need to be programmed or configured or something else other than "Plug And Play"?


2) Is BCM from SAAB 9-5 2.0t, 2010/11 identical for my SAAB 9-4x?


Thanks in advance!

---

Saabaca, on my 2000 9-5, the problem was Cold Solder Junctions inside a bright orange relay, under the hood. Apparently, this relay is activated during lamp tests.

At my workbench, I carefully removed the relay cover from the base and reheated the dull grey solder with fresh solder and rosin flux. Everything looks shiny and it works well now.

Of course, I have no idea how a Cadillac will test lamp filaments.

I do know that a faulty Neutral Safety Switch can cause such a failure symptom, except for the reference to a BCM.

You see, the NSS has one section devoted to dashboard indicator signaling, and has additional independent switches for both the Neutral/Park Position and the Reverse Position. These can fail independently.

Well, after some additional diagnostics, we found that backup camera was almost burned inside (think it was because of ingress of water), causing tricky short to ground (while my diagnosticы showed some resistance in circuit). So BCM was turning voltage off and was right :)

Disconnected the plug from camera - and reverse lights are working OK.

Now waiting for new camera to install.

Thanks to all again!