Immobilizer question Topic is solved

[bmdubya1198]

I think that is an open/short circuit tester. A CANBUS sniffer actually detects and stores Hex commands over the CAN. You need to know if everthing is talking to everything on the car correctly.

I *think* a 1999 only uses CANBUS between ECU, ETM, DIM, and Lock controller 2/76

TCU? (Not sure,but you dont have one on your M56. Well, you do have one, but it is mounted above the driver seat.)

The wiring diagram doc shows the CAN communication modules. I believe it's those that you listed along with the ABS module.

[wizechatmgr]

What voltage are the modules reporting while the car is at idle from VIDA? Does that car ever seem to bog down on accelerating or decelerating?

Was this issue something that slowly started or was it literally it started one day and has happened every day since? Did it follow any weather off the top of your head?

The reason I ask is sometimes one or more modules may be fine, but for whatever reason, the power supplied to them is either dirty or insufficient. A bad stator or brushes can cause dirty power... You'll see excess ripple if you're using an oscilloscope. Computers HATE dirty power far more than the voltage tolerance as it can actually screw up the effective clock signal and A<->D & D<->D signals. Typically symptoms of this are random operation and lockups. The worse the power, the more consistent the likelihood of an issue remaining.