the problem was the ecm system.
unplugging the ecm does not work, try unplugging each component of your
BCM. Example: remove the radio plug-in, security alarm module plug-in,
wiper module, door module, cruise control module etc (do the removal
one at a time and watch your dash to see the effect). The last module
you touched where the dash gages start to work is the culprit. If none
of these work, try measuring the voltage as shown below.
the BCM pin ground supply provided in the wiring diagram. Any
measurement higher than 0.250 volt is a red flag which shows something
is shorted in the circuit. Again these ground pins or connections are
shown to you in a wiring diagram if you are a member of ATS.
the bus pin terminal, they are usually shown as positive or negative
bus connector. Unlike the ecm where you check the reference voltage at
5 volts, measure the bcm bus connector pin and you should get 2.4-2.5
volt for normal operation. If the reading is normal (2.4 to 2.5 volts),
it shows the bcm is OK. You can then replace the instrument panel
first. If after replacing the instrument panel and still the same
problem exist, replace the bcm.
replacing the instrument panel, check with your dealer or ATS to
confirm the programming of your odometer. On most models, the odometer
program is located in the bcm not in the instrument panel. So if you
are replacing the bcm, you have to remove the old one so you can take
it to the dealer who will need it to program your new bcm.