Information Resetting to zero on the DIC Display

[cetheri]

I just started driving my 1997 STS again after having an engine installed (I almost forgot what a pleasure it is to drive this car). It has been down since May of 2005! It's running beautifully, but I've noticed that all of the counter information on the DIC display (fuel used, trip odometer, inst. & avg mpg, etc.) resets to "0" after the car sits for a while (overnight). When this happens, it will not recall my radio station either. If I'm gone for just a few moments and return, then no problem - it remembers everything. Does anyone know what this might be?

[Cadillac Jim]

The battery voltage is dropping below 9 Volts when you start the car in the morning. Check and clean the battery cables and have the battery load checked.

[cetheri]

Jim, Thanks for the quick reply. Keep in mind that the information on the DIC display is showing zeros before I ever start the car. Based on your reply, I went out this morning and checked the battery voltage. It is showing 12.6 at the battery and 12.4 on the DIC display. As soon as I turned the key the information was all zeroed out without ever starting the car.

Is there maybe some sort of small form factor battery in one of the modules (IPC, IPM) that is responsible for retaining the information (similar in concept to a computer CMOS battery)? Scratching my head on this one(???).

[Ranger]

Pull the DTC's.

[cetheri]

Pulled Codes:

PCM P0603 HISTORY

IPC B1552 HISTORY

ACM B1340 CURRENT

ACM B1341 CURRENT

MSM B2120 CURRENT

SDM B1161 HISTORY

SDM B1163 HISTORY

SDM U1096 HISTORY

TCS C1255 HISTORY

PZM B1552 HISTORY

IRC B1740 HISTORY

IRC U1129 HISTORY

IRC U1255 HISTORY

IRC U1064 HSITORY

The ACM codes probably explain the problems I'm having with the dual zone climate control (passenger side always hot). I wonder if the Memory Seat Module code is relevant.

[cetheri]

Additional Info:

IPC B1552 - Keep Alive Memory (KAM) Error. Makes perfect sense. Question is, how to fix it.

Also, the Body Control Module was replaced by the shop that installed the engine. There are also some additonal MSM HISTORY codes that I need to go back and retrieve (ran out of time).

[Cadillac Jim]

PCM

P0603 Control Module Long Term Memory Reset

IPC (Instrument panel)

B1552 Keep Alive Memory (KAM) Error

ACM (air conditioning)

B1340 Air Mix Door One Movement Fault

B1341 Air Mix Door Two Movement Fault

MSM

B2120 Lumbar Up/Down Sensor Failed

SDM (air bags)

B1160 Loss of Serial Data - VIN Not Received

B1163 Loss of Serial Data-No Lamp Response

U1096 Loss of Communications with IPC

TCS

C1255 EBCM Internal Malfunction (ABS/TCS Disabled)

PZM (body and chassis)

B1552 Keep Alive Memory (KAM) Error

B1740 Driver Seat Front Down Switch Circuit Malfunction

IRC (radio)

U1129 Loss of Communications with AMP

U1255 Class 2 Communication Malfunction (Serial Data Line Malfunction)

U1064 Loss of Communications with DIM

CURRENT CODES

The ACM codes may be caused by a vacuum leak. The lumbar sensor failure is probably due to the lumbar position being against the stops, probably all the way down and all the way back. Move it a bit and this code will likely go away. The B1740 may also be due to the seat postion being aginst the stops but it will go away by iteslf.

All the rest of the codes look like low battery voltage while starting -- the battery voltage is dropping below 9 Volts, proobably by a couple of volts or more. This can be caused by a low battery, dirty or bad battery cable connections, or a weak cell in the battery. Generically speaking a shorted or bad starter can do this but I've never heard of that on a Cadillac.