I have then above 4 lights on, on my 2002 monte LS. This started two days after I went through a new car wash here. I drove home, without lights, parked the car and when I started it a few days later I had the lights. I checked all of the wiring and could not find anything wrong. I disconnected the battery, reconnected it, and all of the lights were gone. I drove it a couple of times without lights, and then a few days later when I started it, there were the lights. I rechecked everything I could, and thought the right rear wheel sensor might be an intermittent problem. So I replaced the wheel bearing/sensor. After disconnecting the battery and reconnecting it, everything appeared ok. Again a couple of days later there are the four lights. I purchased a code reader and checked the car. I found several codes which I cleared thinking that might be the problem. I restarted and drive the car with lights on I might add. I took new readings for the codes, and got the following: U1040, C1248, C1254, C1298, and U1000. I am thinking I might need to replace my ABS module. Any opinions would be appreciated.

 

I have the same car, same sitch, the GM garage told me it was a wheel sensor (part of the wheel hub) that was bad, and said it was the RF hub. Others have had the same issue, and it is more likely the wiring, and that it gets 'stretched and brittle' and sets everything off. I've been driving mine like that for a couple years, someday I'll look closer at it. There are videos on YT that tell how to test the wiring. . .
On a related note, I bought an 05 Buick Lacrosse this summer - wouldn't you know it, it is starting to do the same thing. Must be common with early 00's GM cars that takes a while to wear out. Go figure.
Good Luck, and welcome to the site!

 

I have checked my wiring and the sensors, and they all appear to be good as per the ohm meter. The wheel sensors are not too bad to replace, but you have to replace the entire wheel bearing since it is a package unit. Nice to know you can drive it, I just hate the lights.

 

One of the tricks about these wheel hubs is if the seal on them begins to fail and let moisture in, it will cause the car to trip codes. I have dealt with that a bunch. So you *might* get a good ohm test. Best course of action is to just work through the system to determine is if it the wiring from the sensor to the EBCM or the EBCM itself. I have yet to here a monte/w-body EBCM fail (helps that it is up high, hard for weather and road conditions to impact it). But there is a first for anything. If the codes are intermittent, that is a big annoyance!

 

How do I check the wiring and sensors if I cannot use the ohm meter?

 

You can still use the ohm meter for the wiring to and from the EBCM (i believe it requires disconnecting the main harness from the EBCM, disconnect the speed sensor and short out the wiring at the speed sensor (that goes to the EBCM) and then taking an ohm reading at the EBCM harness to ensure you have continuity. If that rings out good for all the sensors reporting issues, then you know the wiring path from sensor to EBCM is good. Granted, I guess if you check continuity using a ohm test from the EBCM with the speed sensor correct and it works, you could also assume the wiring is good.

Next start checking power and ground connections for the EBCM with the volt meter. And potentially find the pathing for the data connection for the EBCM to the rest of the car and with the batter disconnected, ring that out with a ohm test and make sure it is right. I did some quick searching to get an idea of the codes you have going on... And none of them appear to be speed sensor related if my read is right. So as much as it is rare for the EBCM to not be an issue, this might be a case where it actually is. I would start with making sure the power and ground is working. If it is, look into a replacement (junk yard part in my book due to the high cost of a new one and the fact they normally don't go bad) EBCM.

 

Next start checking power and ground connections for the EBCM with the volt meter. And potentially find the pathing for the data connection for the EBCM to the rest of the car and with the batter disconnected, ring that out with a ohm test and make sure it is right. I did some quick searching to get an idea of the codes you have going on... And none of them appear to be speed sensor related if my read is right. So as much as it is rare for the EBCM to not be an issue, this might be a case where it actually is. I would start with making sure the power and ground is working. If it is, look into a replacement (junk yard part in my book due to the high cost of a new one and the fact they normally don't go bad) EBCM.[/QUOTE]
I have already checked the wiring as you said, checked the sensors by themselves, and checked them hooked up to there wiring at the plug going to the EBCM. I'll check on the voltage and ground next. What do you think of having my EBCM rebuilt? Looks like I can get it done for less than $200.00. Thanks for all the help

 

I guess I did not reply correctly, so here is my question again. Which do you think is better? Sending my EBCM out for repairs, or buying aa used unit? Used scares me. Thanks for your input. I've checked all wiring and power, and all appears ok. I guess now is the time to start replacing parts, or take it to the dealer, that would cost a fortune.

 

Sounds like you did your due diligence on checking the wiring. My opinion, I would grab a salvage EBCM for about $20. They rarely fail (obviously it happens). For example, the EBCM of my Grand Am when bad because the weather seal on it failed (longer story why). I got a salvage EBCM for $20 (instead of a $200+ replacement). Been working fine for over a year now. And the EBCM on the Grand Am vs the Monte are not identical but very similar. If this happened on my Monte, I would do the same thing (grab a clean salvage one).

 

I have not had the best luck with used parts, so I decided to go with a rebuild of my ABS module. I sent it off yesterday and should have it back in about 2 weeks. The car started acting real odd a couple of days ago. The brake fluid level light came on, and the instruments in the dash quit working, including the AC. When I got home and turned the car off, some of the warning lights on the dash would not go out. I plugged my code reader in to see what was happening and everything went back to normal. I had 5 new codes. I erased them, and after restarting the car, they did not come back. I don't know what that was, but I will find out when get my ABS back and reinstall it.