I have a 97 Rodeo 6cyl 4WD (alt. Passport) The rr.abs and brake light is on. I replaced the ABS sensor (location differential) replaced the abs controller under the passenger seat. I changed the parking shoes,brake pads and adjusted emergency brake and bled brakes. Still dont work and light is on. I did a ACTRON DTC code check P1391 wheel speed sen 1 circuit performance. Where is this sen 1 located. I am starting to feel i have exhausted all options even replaced the abs i guess modulator( i dunno) which is located rear right connected to vacuum hoses / box. What is a G sensor? Some insight on this is so deperately needed. It is killing me that i dont get the pulsing in my brakes..(and extra safety as well. I tow a boat):banghead:

There is only one sensor in the rear diff. Check the connectors in the wiring as they travel from the diff to the front of the truck. I haven't been able to solve this intermittent problem on my 97 either.

FWIW....have the same issue ongoing for the last 4-5yrs now, truck still drives and brakes the same with or without the rear ABS system, I too tow a heavy boat with this truck and drive a lot of mountain passes. The truck brakes no different then it ever has.

If the truck was 4-wheel abs you'd definitely have the added security, etc. but with only abs on the rear, there's not a whole lot of difference from that versus a regular braking system.

Also...just a thought, have your alternator checked for correct volt output while under load, meaning it should put out nothing less then 14V...if it is, your problem could be linked to that.

I know it sounds weird, but all of the lights you mentioned that are on on your dash are the same exact lights that come on when the alternator is failing......could be where your headache is.

+1 on the alternator.

Yes, that do sound weird about the ALT. I will try testing it. This alternator was replaced 6 years ago. Do we know what a g senser is??? The p1391 code came up MAF sensor and or G sensor failed...??? I dunno.. Ohh, i forgot to let you know i have been having this problem for 5 years now.. It is only now i am taking the time to try and figure it out. I ended up taking the bulb out since they wont pass my state inspection if the light is on brake or rrabs.... such a pain..

I found something in the Trooper forum about the G sensor. Apparently, it senses when you are off-roading or otherwise driving on rough terrain and the ECM uses this information to make adjustments to compensate. At any rate, it sounds like it has nothing to do with your brake lights being on.

I had a feeling in my research as well that it had something to do with off roading vertical and horizontal positioning of your vehicle but i could not confirm. Or if it had any relation to the ABS.. Thanks for that insight, good to know

The only sensor is in the rear driver side, check the wiring and the pigtail connector for mud which will obviously cause a poor connection. Also there is a recall on certain models that you may want to check into for the abs module - this is a safety recall so the dealer is required to replace it at no charge.