ABS, TCS and BRAKE lights and NO CODES

[bighank]

Have ABS, TCS and BRAKE dash lights AFTER starting the vehicle. The green led in the TCS momentary switch is off, and pressing the switch will not turn on TCS. Fuses for ABS and TCS check out good. With ignition on and not started the warning lights are all off. Pulled both front wheels and disconnected sensors at wheels. Results: Both sensors read ABOUT 1080 OHMS (RIGHT IN THE MIDDLE OF GMs VALUES im Service Manual), and not shorted to ground. Resistance up the harness is about 40k ohms on both sides with no shorts to ground either (THERE IS NO VALUE GIVEN FOR RESISTANCE UP THE HARNESS TO THE EBCM).
With both sensors REMOVED the 3 dash lights come on IMMEDIATELY after turning on the ignition and stay on when you start the car. Replaced both sensor plugs and symptoms are as first stated ... lights off when ignitiion on but engine not running and then come on when engine is started.
Used a Toptak TP-300 scanner and got NO CODES WHATSOEVER.
Went to Advance Auto and used their new ACTRON scanner. Once again NO CODES WHATSOEVER. Do I have to go out and buy a Geniscan MaxScan VAG405 scanner for $160 to read ABS codes? Specs for this found at www.alpha-bid.com. While it says it can read ABS, airbags, auto trans, and service reset function(?????), not sure if this only applies to the proprietary protocol for VWs and Audis or can it do this for GM vehicles also.
What do I do NEXT? BIGHANK

[1Bradymichael]

I am wondering if you have a ABS pump/modulator issue?
Does the pump cycle if you take it down a gravel road or slippery surface?

[bighank]

Entire systen is DEAD. With key turned to ignition ON the ABS TCS and BRAKE lights do the bulb check and go OFF. Then you START the car and all 3 come on solid. No shorts to wheel sensors. Brake RELAY functions and supplies 12 V to EBCM and Solenoid fuse. After taking off the ECBM and measuring voltages and resistances in the three connectors (C1, C2, C3) reassembled and turned on ignition. Started car. NO LIGHTS . BUT HOLD THE APPLAUSE. As SOON as I STEPPED ON THE BRAKE...ALL 3 LIGHTS REAPEARED. Can hear some movement in the front. Like 2 distinct clunks. Think it may be the soleniods. Haven't checked resistances for the brake MOTORS. Not sure values are in the GM Service Manual. Values for all wheel sensors is about 1080 ohms and no shorts to ground.
Don't want to spend a FORTUNE on an ECBM or other module if it isnt the culprit. Wish I could read out some codes. BIGHANK

[bighank]

Is there anyone ALIVE OUT THERE?

[Judysvan]

Sounds similar to prob I had with rear brakelight assys. Once I wired around the (leaky) plug and thin metal bayonet fittings into the housing assy and soldered some 16 gage wires to the proper metal leads for all the wires, not only did the faulty brake lites and turn signals quit going out, but also the TCS and ABS lights went out... that was a year ago. No probs since then with any of them.

I know it sounds crazy that a light housing would affect the TCS, but there is feedback to the 'puter about the brakes being on, so that affects it when the TCS turns on or off. No TCS = no ABS either I guess is the ans.

Also, it helps to go into the housing from an angle that will be less likely to have water invasion and give it lots of electrician's tape around the wire at the entry to the housing, jaming it in tight to seal er up.

Hope it is as simple as that.

[Malipoopoo]

I have the same thing going on with my '99. Mechanic said its the ABS Motor. Could spend 500-600 to repair it or just deal with it. He advised just deal with it. Not sinking any more money into the piece of crap. So what if I don't have ABS or traction control.

[mhall02]

I have the ABS & TCS light lit up on my dash now for the last few weeks ('99 Montana as well), have replaced both front hubs and still lit up. I would venture to guess it is the ABS motor as well, when I turn on the ignition, I can hear it make a noise and when I start the lights stay on. Once in a while I don't hear the ABS when I turn on the ignition, no lights remain on in the dash, but they do come on later. When I pulled the ABS MOD fuse, I don't hear the ABS engauge at the turn of the key, but still have the light. I think I'm going to pull the fuse and reset the computer and see if the lights stay off. This is the first vehicle I have ever had with ABS and Traction control, so I can most likely live without it, I would just like to get rid of that light in the dash.

[Malipoopoo]

Always thought traction control was pretty useless. ABS would be nice to have back though for those winter snow storms! Let me know if anything works out the prob. Yah, those lights are annoying, especially while driving 14 hrs straight thru the night. Ended up putting one of my business cards over them to block them out!

[McShaken]

I had something similiar, but it was because my brake fluid was low. After adding fluid, everythig works as expected.

[mhall02]

How low was your fluid? Mine is just a tad under the full line (maybe 1/4").

[Spidah]

Judysvan posted a comment about the rear taillight assy.
I am experiencing the same symptoms - ABS/TCS/BRAKE warning lights stay on while the engine is running. By the way, the problem began after a torrential rain. Can you explain where/how you accessed the rear taillight assy - was it the left or right side? The mechanics say I need to purchase a new module for $1200-1300. I'm not too confident in it because it has been intermittent (much like a short) and they said the problem is "probably" the ABS/TCS module, but were not 100% certain without replacing it and retesting. Sounds like a costly "test" to me!

[Judysvan]

Spidah... your symptoms sound exactly like mine were. I had to do both sides. Each tail light assy needs to be removed/dissassembled/fixed. The fix came from a combination of fixes from this site. No re-ocurrence for over a year in any of the symptoms.

A six sided star nut driver will get the assy off of the van. Once you get it off, you can see how to get to the assy behind the lens. The problem that needs fixing is the fitting on the top is not water tight and water gets down into the main pwr bayonette prong and causes it to short out. Also, the pwr prong is not nearly thick enough to carry the load of current necessary, and the others arent trustworthy, either. That plug at the top needs to just be sealed over and all the wires going to it need to be direct (hard) wired thru the housing.

Get the assembly apart from the lens & remove the bulbs (in an order you can remember). Any blackened ones may need replacing. Next, the two part plastic case needs to come apart. With a few regular screw drivers to hold the plastic tabs away from their latches, separate the two plastic housing halves. Inside will be some metal bars which feed the juice to the bulb connectors. It may take a little time to figure out which harness wire lead connects to which bar, but it needs to be done.

Next drill a hole in the lower part of the housing at a spot that will not get soaked in a big rain and still allows room to run wires back to the loom. Cant remember size of drill bit, but not so big it cannot be plugged, not so small you cant get ALL the wires to go through it. Hook up the wires to the bars & solder em down, making sure the bars can each go back in their respective support tracks.

Feed the wires thru the hole, test your wiring by hooking up those wires to their respective wire in the harness and put the lights back in to make sure the turn, brake, backup, etc lights all work properly. Then tape the housing hole & wires tight, so no water can get in. Make tough connections into the harness and cover generously to seal tight with good electricians tape. Re-assemble into lens, & replace into the van.

The big surprise to me was that by fixing the brake light, it somehow also fixed the TCS and ABS light. The brake lite somehow feeds a signal into the TCS and ABS which needs to be good before it can work properly. The turn signal was also a must fix. You can replace modules all u want, but unless the light housing is fixed, they aint gonna work. It isnt hard or expensive, but takes a few hours to get it all done properly with patience.

Happy wiring to ya,
Judysvan