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THIS IS WORK IN PROGRESS I will also update with more pictures. I'll be adding 98+ info later.

Ok, I assume that the majority of people on this forum have been plagued with that orange abs light. Well hopefully I can help some of you get rid of that dreaded light and also the Low Tire Pressure Light. I have been dealing with my abs problems for almost the last year and I can say I almost know everything that can go wrong with the system. I'm first going to inform you have the main components of our abs sytem (note this applies to 97 GTP and a few other years of grand prix). Some models have traction control which is almost the same but slightly different. If you have the LOW TIRE PRESSURE LIGHT ON, this means you have a wheel speed sensor problem, wiring or wheel bearing, CHECK FUSES FIRST. If only abs light is on, you have low voltage or abs main component failure (example: abs motor pack, abs relay, fuse, modulator seized, EBCM, ect).

This part is Called the EBCM (Electronic Brake Controlled Module) behind it is a relay that is attached to the plastic tray that holds the EBCM

Part 1= Master Cylinder
Part 2= Brake Modulator
Part 3= Brake Motor Pack

24 Way EBCM Connector

8 Way EBCM Connector

Brake Motor Pack Connector

Front Speed Sensor Ohms

Rear Speed Sensor Ohms

Rear wheel Speed Sensor Harness

Rear Wheel Speed Sensor Severed by Trailing Arm

Rear Wheel Speed Jumper Connection

If I had to diagnose my car all over again (ABS light/Low Tire Pressure Light) , I would go straight to the EBCM 24 Way Connecot (blue color) on the back of the EBCM. Here is a electrical diagram of the 24 way EBCM Connector. To remove EBCM here are the basic steps.

1) Remove the driver side carpet thingy that holds the light bulb (pull it down).

2)Next take off the plastic dash part above this as it makes it easier (remove the tire pressure reset switch.

3)Now move your driver side seat as far back as possible as this will give you more space to lie on your back.

4) Now remove the all the electrical units (should be 2) on the EBCM tray (will be on right side). You will have to push up or down on them to get them to come off.

5) Next remove the 3 relays (2 gray and 1 black that are on the front side of EBCM). To remove push left or right (I forgot which way).

6) Now remove the 2 bolts (1 is between brake emergency pedal and EBCM/Other is on Right side of tray)

7) Now pop EBCM out of tray by pushing up and pulling left while other hand is pushing tray down and to the right.

Now you'll see the 2 different connectors on the EBCM. MAKE SURE TO TURN YOUR IGNITION OFF OR BETTER YET TAKE YOUR KEYS OUT

1) Now remove the 24 way brake connector (blue one). You'll have to squeeze the blue connector and pull it and move it side to side (first time I did this I was worried about damaging the connector). Just try not to be tugging a whole lot on the wires if at all possible.

2) Now you'll need a DVOM (Digital volt ohm meter, you can pick up a cheap one at sear for like $25 or get a better one for $55).

3) Now we'll measure the wheel resistance at the ebcm connector to see actaull what your ebcm would be reading.

4) Take DVOM and turn it to ohms meter (2k setting works good). Now take leads and match up each wheel speed sensor HIGH and LOW (refer to 24 way connector above). DO NOT JAM LEADS IN SO THEY STAY IN BY THEMSELVES AS THIS WILL DAMAGE CONNECTOR ONLY TOUCH THE CONNECTOR PRONGS

Examples are: A2,B1/A3,B2/A4,B3/A5,B4

5) Check your restistance by using the chart resistance above. Make sure to use front chart and rear chart accordingly. If you have 0 resistance (I had 3 zeroes=1 spliced wire and 2 bad rear speed connectors that actually attached to wheel hub) that means either you have a splice in your wires somewhere or a bad connector between the Wheel speed sensor and your ebcm connector. I bought all new wheel hub harnesses from ED MORAD for cheaper than 1 brand new one from GM.

6) If you register 0 on DVOM now disconnect the speed sensor connector that attaches at jumper harness check resistance, in wire.

7) If 0 then you have either a bad harness or a bad connection at wheel hub.

8) When all of the shorts/Bad connections are fixed, then your Low tire Pressure Light will go off (IF your lucky then your abs light will go off also).

If your abs light is on, Then you will have a more serious problem which requires an abs scanner (I have one and might think of renting it but not quite sure yet). I had this light on also, however I think I may have caused this by jamming my DVOM meter leads into the abs motor pack connector. I took a tiny screw driver to bend the prongs back, and that fixed my abs problem once I cleared the code. Hasn't been a problem yet for 2 weeks sinced I fixed it.

If that fixes it reassemble everything. Sorry if I'm vague a little. If people need more info please feel free to ask.

If people are interested about renting SNAP ON SCANNER (reads abs/engine/transmission/airbags) let me know. As I'm thinking about it, not sure yet though.

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