abs and tt4 lights are on

Hummer H1 and Military Humvee topics
ysrjunkie
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Re: abs and tt4 lights are on

Post by ysrjunkie » Sat 01 Aug , 2009 8:40 pm

Nice work Drew! I've been wondering about an alternative to the astronomical A.M. General module complete repair.

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chuck
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Re: abs and tt4 lights are on

Post by chuck » Tue 04 Aug , 2009 8:19 am

I'm still here. For some reason I didn't get the updates. Maybe they got lost in my spam filter.
I'm going to use the info in these posts to update the article. If you have more send it along and I'll watch for it.
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Riveted
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Re: abs and tt4 lights are on

Post by Riveted » Fri 23 Dec , 2011 6:43 pm

New to the forum...previously a lurker and was able to use the info to repair ABS 2-6 failure. FYI...not a mechanic, used to be stationed aboard submarines about a million years ago, so this stuff doesn't scare me too much.

Latest info. Falconworks makes a rebuild kit for the shuttle valves and seals. Made for the Discovery II, but matches up with 2002 H1 ABS just fine. Once taken apart, the ohm readings were fine on the old shuttle valves, but the soldering on the connector seemed to be the problem within the ABS modulator. When I jiggled the wires on the new shuttle switches, I lost ohm readings which is the source of 2-6 fault code. Once I scraped off the plastic behind the prongs and re-soldered the pins (I left the old connector plugged in so the pins would not fall out when re-soldering btw), both the old and new switches gave constant and proper ohm readings.

http://www.landroverclubvi.com/abs-mod.html
pic 33-37 shows the source of the problem.

There is a work around to the entire black plastic connector problem that is included in the instructions. Apparently the black plastic connector merely sends signals from the shuttle valve switches (2 white round switches inside the black plastic housing under the ABS modulator) to the large 13 pin connector in the rear of the ABS modulator. Since the source of many problems is this internal/infernal piece, the wires from the shuttle valves can be run through the black plastic covering and one wire is simply grounded to the chasis and the other is connected to the wire corresponding with the signal pin. In the land rover it is shown in pic 42-44 of the link above. I was able to re-solder the internal connector so I will leave it as is, but I would need to verify the same color wire in the harness if I continue to have problems.

Getting the modulator out is a real bear. Not anywhere near as easy as you see in the Land Rover examples. Like delivering a 12lb baby with 9 umbilical cords from a 100lb mother.

The shuttle valves were unnecessary to replace but I already bought the kit for about $135 (Dec 2011) so I changed them. The seals on the internal pistons were leaking (I think). There was a lot of brake fluid residue around the unit so I assume it came from the leaky seals. The two seals are on the pistons for the shuttle valves themselves (1 seal per piston). Per Falconworks, after about 60k miles the seals begin to leak and I have around 60k miles...and I have a very small leak. But the leak did not seem to cause the fault, it was the crappy soldering job that requires the same amount of work to repair as rebuilding the seals/switches.

Basically if you get a 2-6 ABS failure, it is probably just a bad soldering job that can be fixed very easily...once you move heaven and earth to get to it.

Now that I have the left spray shield removed and room to work in front of the master cylinder, any recommendations on maintenance that should be done in this area?

Thanks for your previous information, it really helped me out. I hope this info helps someone.

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chuck
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Re: abs and tt4 lights are on

Post by chuck » Fri 30 Dec , 2011 3:45 pm

Thanks for the info. I updated the article on the Flash Off-Road site so the next owner will have the benefit of your experience.
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95 Gas Wagon
96 TD Wagon
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Nakdiam
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Joined: Thu 06 Jun , 2013 12:36 am
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Re: abs and tt4 lights are on

Post by Nakdiam » Thu 06 Jun , 2013 7:21 am

poco1971 wrote:I found your website after having this same problem. ABS and TT4 lights were both on. I had no clue what I was looking for but it was pretty simple. I had some mud between the ring and sensor. I cleaned them all up and adjusted as you guys had said. Lights are both off now.

Thanks for the help.


Dean
I'd a problem with my TT4 light. But recently I fix it. But that website is really helpful :-)

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