[batejd]

My DIC and odometer are dead on my 98 STS. Temp guage, tach, speedo, and fuel guages work fine.
I checked all connections and grounds - OK All fuses are good.
Checked voltage at Circuit 440 and 41 - oK
No voltage at Circuit 1369 Yellow (should be 55 volt)
Replaced IPM -no better
Any ideas?

 

[N*Caddy]

Are the Radio and Climate control displays working?

 

[batejd]

Yes, radio and climate control are working.

 

[Raze]

Do all of your dash lights work at night? You can check by putting something like a shirt over the light sensor on the dash (little dome thing) and then turn your lights on, if only some of them come on, I'd recommend pulling the gauge cluster and checking for burned out bulbs that might have burned the board, I've burned out quite a few and they can burn up real bad sometimes actually discoloring the board. Some are even close to critical parts like resistors and the like and if they burned up these you'd have trouble and may have to replace the cluster...

 

[batejd]

All the dash lights and gauges work fine. It's only the DIC display that is dead.

 

[N*Caddy]

Yeah, I understood your problem, this is why I asked about the other displays. There is a low battery protection mode that shuts down all the VFDs on the car (the IPC is the one commanding them off trough the data bus, shuts down his own and command the others). This happens when the IPC sense the voltage dropping below 9.? Volts.
In your case seems to be a problem with the IPC.
Read this basic information about VFDs so you have an idea in what you are getting into.
Unfortunately I haven’t study the IPC circuitry enough (especially the ‘98+ models) but you might get by replacing boards from a used working IPC and keep the odometer (that in case you really want to keep your IPC). Probably you will get by easily with completely replacing the IPC and had the odometer reprogrammed.

 

[batejd]

Thanks. Replaced IPC with used one and display works. I now own an extra working IPM if anyone needs one!