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[NO_ADS]First of all... I have searched many posts about ABS lights, DTCs, etc. The information is scattered, unreliable. Now enjoy my somewhat lengthy anecdote...

The ABS light in a 2004/5 Tundra Access Cab (2UZ-FE, with 50k miles) has been illuminated constantly since the owner got stuck in a snowdrift. . The driver engaged the ABS system on the way into the drift. Then, once stuck, spun the wheels excessively while trying to escape. Truck was towed and had a flat tire

No other lights on, No other issues (aside from a cracked bumper) and the lack of ABS.

Visually inspected sensors and cables, and they seem ok. Removed battery power for 30 minutes. Light still on. Flat tire repaired (light was on while spare was installed as well.) Truck has been driven for at least 10 cycles since light was first ON.

Is there a way to check the DTC codes without an OBD-II tool? I know that I can go to a local auto parts store for the codes, but I am looking for a DIY procedure. I found a short turorial on another forum, but it seems incomplete.. or for another Toyota..

connect terminal 4 and 13 of the OBD-II socket...with a jumper wire. Turn the ignition to on. You'll notice lots of flashing lights, but just pay attention to the ABS light... If it has stored a trouble code, it will be flashing a pattern that will coding a two-digit number... etc
The terminals aren't numbered. I have the Tundra FSM but it doesn't mention the ABS light, two-digit codes, or any procedure without an OBD tool. To make matters more confusing, every list of DTC codes I have read over doesn't mention the braking system...
Is there another tool/procedure/computer/manual that needs to be used?

Anyone have a Chilton/Haynes/Bentley repair manual with this procedure? Or a photo of the OBD-II that is NUMBERED?

Why is the light on?

Thanks for reading this FAR!


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jumping wires around a connector because you saw it on the internet is never a good idea. What good is knowing the code but not what it means? Just go to your nearest auto store, that is your best option.
 

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05' Tundra (Tun-Tun)
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the jumping thing might work...but no way in the world i would put a jumper in my OBDII port :D but then again i have a scangauge so i can easily read codes
 

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I've only heard of jumping wires for codes on older computer controlled engines(80's-early 90's). Sure it may work, but there is no way in hell I would jump any wires on a OBD2 equiped vehile. Its just not worth the risk imo when you can get it done for free.

My guess as to why the light is on would be that either a ABS wire got damaged or some snow/ice got into the wheel speed sensor.

Also, what do you mean by "The driver engaged the ABS system on the way into the drift."? Do you mean he loked the brakes up? Im just a little confused because there is no way to turn ABS on or off.
 

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Discussion Starter #8
Everyone, Thanks for your replies.

05DC451, Thats what I wanted! Thanks!

Sorry for the confusion, tundra05_trd. You are correct. The driver locked up the brakes, then hit the snowdrift. The vehicle has been allowed to warm up long enough for any snow/ice to have melted by now. Possible some dirt is still in there.. I will check all the sensors again.

I read that local parts stores do not have the equipment to check ABS/VSC codes... just generic Engine codes. Any firsthand experiences?

To anyone who has tried this: Did you use a fused jumper? What rated fuse?
 

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Not sure. Like I said, it's simple to jump the pins and count the flashes. We jump wires to troubleshoot different stuff at work all the time.
 

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Discussion Starter #10
The blinking ABS light spat out ABS codes 31, 32, 33, 34, and 41.

According to the link 05DC451 posted:
31-34 indicate trouble with the speed sensor circuits of all four wheels...
41 says Battery voltage too low or high. Check charging system.

Battery related codes stored in the ABS ECU? Really?
I will be checking the charging system, but as far as the sensors, could all four of them really have gone bad at the same time? Not likely, so its either the wiring.. somewhere... or the ECU. Since when does locking up the brakes in the snow cause an ECU failure?
This is starting to look expensive.

I traced, wiggled, and prodded all four sensor wires as far as I could until they entered harnesses and disappeared into the depths of the chassis.
Next up: Sensor resistance check.

I also could not get the DLC to reset. I pumped the brakes as fast as I could (several times/second), and even had a companion verify the brake lights flashing while doing so. The ABS light stops flashing while Im pumping, after which it goes back to blinking codes. Why wont it reset?

Does anyone have a complete copy of the Tundra FSM or at least the ABS Diagnostic section that is missing from the ncctora site? I know it exists because i found this.

New Thread Starter: My rusty bars. Is there a manufacturer of [NO_ADS]Nerf bars[/NO_ADS] that dont rust??
 

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Do these have a seperate ABS ECU? I would start checking wiring and connectors to whichever ECU controls the ABS. I would bet a wire or connector was damaged or got water in it either in the snowbank or when being towed out. I find it improbable that all 4 sensors quit at the same time. As for the battery code, the ABS systems I work on run off a seperate ECU and will throw a voltage code for high or low voltage.
 

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Discussion Starter #13
05DC451, Yes the ECU for the ABS system is separate and mounted in the engine bay on the passenger side close to the firewall. Nearly impossible for the impact/tow to have sprayed it. (I have considered that the tow truck driver may have sabotaged it!) I checked the voltage at the ECU and the battery, 12.2 volts with IGN off, 14v while running. You also mentioned that you checked the DTCs when your ABS light was on. What codes did you get. And what was the culprit?


Thanks for the link, kanaduh. And for the lead on the steel steps! :ts:

The 00-03 FSM was my guide today as I tested all the fuses, speed sensors, sensor wires, ECU connector wires, ignition power wires, and ground wires for breaks and shorts. All resistance measurements were within factory specs. The good news is that I do not need to replace sensors (about $200/each) or replace the wiring harness ($unimaginable). The bad news is that its looking more and more like the ABS controller ($200 - $600) is malfunctioning. The decision I am facing now is whether to bring the truck in for an ECU test ($$$) using a computer or to replace it on my own and hope that fixes it and it doesnt BRAKE (roll eyes) again.

I still find it hard to believe that the ECU failure and the impact are coincidence. If not, then what caused the computer to malfunction? Will it happen again the next time someone locks up the brakes? Or gets a flat tire? Or parks in the snow?

Would a voltage spike (16+ volts) cause an ECU malfunction that didn't trip the fuses?


For those interested... the ABS ECU connector in the 1Gen manual is different than in the 2Gen Tundra. This means that the wires are in different locations in the connector and also that ABS units are not interchangeable between generations. Luckily, the wires that run from the ABS ECU to each speed sensor have distinct colors and they are easy to get to. The front connectors are in the engine bay mounted on the frame rails against each wheel well. Both rear sensors connect to a single 4-wire connector mounted on the rear of the fuel tank, easily seen from the LEFT REAR wheel well (Rather than under the rear seat as the manual states.) All connectors are GREY in color and have locking tabs.
 

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The code I had was for RR ABS sensor. I replaced the axle seal and cut the o-ring when I reinstalled the sensor so it wasn't seated right. R&R o-ring. Problem solved.
 
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