97 PA What Changes?

Concerning the elec system... What is different with the vehicle elec system once the engine is running versus when the key is in the "on" position (last click before the start position)

In the "on" position everything is good on the dash (lights) and the traction control light works in sync with the button. Once the engine is running the ABS and Traction lights come on and stay on. The Traction Control button has no effect on the light.

Thanks!

The initial key on position allows you to tell if the warning lights in the dash are in proper working order, sorta like doing a test of the light bulbs and the computer links to the warning lights.

When the engine is started, the system automatically goes from test mode to operational mode. If you still have lights on, then there is a problem with those particular systems that need to be fixed.

Your problem could be related to the following system failures listed:
1. Power Train Control Module
2. Vehicle Speed Sensor
3. Wheel Speed Sensor
4. Wiring harness problems

It would be to your advantage to have your DTC codes read to find out which system needs trouble shooting. Your local auto parts store can read these for you if it means they will get your business.

It would be to your advantage to have your DTC codes read to find out which system needs trouble shooting. Your local auto parts store can read these for you if it means they will get your business.

Are you sure the typical auto parts stores can scan for and retrieve GM Mark VI ABS System related ABS and Traction Control System DTCs? Last time I checked you need an ABS capable scan tool or a GM Tech II.

If it is a speed sensor problem, a code may be set. If no code is set then the ABS unit may have to be tested. Trouble shooting the ABS unit itself may take a special scanner.

If it is a speed sensor problem, a code may be set. If no code is set then the ABS unit may have to be tested. Trouble shooting the ABS unit itself may take a special scanner.

What speed sensor are you referring to? For example a defective VSS (vehicle speed sensor) will normally trigger an odb-ii type DTC like PXXXX and the SES/CEL light. This is not necessarily a speed sensor or wheel sensor issue. It could be the EBTCM module based on the symptoms. The four wheel sensors are not checked until the second part of ABS initialization and testing until the vehicle has reached a speed of around 10 mph. Based on the OP's original post it looks like the ABS system has failed the first part of initialization. An ABS capable scanner must be used to retrieve ABS/chassis related DTCs, run diagnostics like wheel sensor comparative output and test the EBTCM module which is the brain of the ABS and Traction Control System. ABS and traction control system DTCs are Chassis related and start with C. I.E. - CXXXX. To set an ABS fault light a DTC is normally stored so it should be there for retrieval with the proper equipment.

ABS is probably the most complex and troublesome system on my 97. I ended up going to the dealer and they were stumped for two days and it cost me $400. A loose wire on a wheel sensor I was told, sounded a little hokey to me. Anyway the light came back on a few months later and I wasn't going to raped again.
I never use the ABS and really don't care if it works. I took the 4 screws out of the dash and took the bulb out, at the same time I installed a stand off to keep the gas gage from pegging out. Took may be an hour.