4LO 4HI flashing, ABS & Traction full on

I just wanted to put this out there, Had this issue on a 2011 tundra. Dash looked like a disco. The code reader said "open circuit right rear” That is your wheel sensor. First, before you fall off your wallet and start tossing parts at your truck, along with a big hammer, take a moment and do some testing. the harness that runs to the left and right wheel sensors is located just above your rear axle. disengage the right side just behind the wheel (plastic clip with outer cover safety clip) and follow the wire to a vertical case that holds the left and right wires (from axle to underside of bed). up under the bed of the truck, you will see a clip. unclip it. you will see black, white, green red, on the back of the clip. (Black white is RR green and red LR). a continuity check of the RR by jumping out the RR harness at the wheel and checking at the clip part still mounted to the bracket up under the bed. if you got continuity there then move on. if not replace that short harness. If it’s not the short harness, you need to check the sensors. unstrap the wire along the axle till you can take that end (RR) and reach your left rear wheel sensor. unclip your harness for your left rear wheel sensor and clip in the right wiring harness into the LR. Reclip the connection under the bed up high! see if the code reader clears RR. yes LR will now show but that's OK. If it still shows RR is open, you ruled out your sensors, now you got a broken wire in the RR harness. replace all wiring back to the factory. . go to the engine compartment between the air filter and firewall and remove the small plastic box cover. remove 1st clip (long and white) closest to the RF wheel. lift - in the center is 4 pins. you will be working with the underside of the clip-on top, not inside the box. find the white and black wire (will be in line with the green and red) toward the middle of the clip. using a continuity reader short out black to white on the clip in your hand (just put a jumper in ports) and go back under the truck (hit head) to the clip under the bed unclip it and check for continuity between Black and white off the clip in your hand not in the bracket. . if nothing, back to the engine compartment and jump white to green on the clip, back under the truck (hit head again) to check the continuity between white and green. if you got continuity then it’s your black. if not back up to the engine compartment and jump out black to green, yup you got it, back under the truck (yup, hit head again) and check for continuity between black and green. if you got it, it’s your white wire. Rerun a new wire from the engine compartment box to just before the clip under bed. Cut factory wiring and splice in new wire to replace whatever color you are working with. All lights will go off and you will be able to engage your 4-wheel drive again and take care of the bump on your head.

 

You are the man been betting my head in on the dash light flashing code said RR sensor open. When I found you post and ringed out my wires and sure enough I have a broken black wire between the front and back plug than you for your post saved me. This truck has been babied since 24k and now has 120k not sure why I have a broken wire but going to investigate now. Make sure there is no tight spots that should cause a broken wire

 

I just went through a set of events with Check eng light code P031, Traction control off then back on while sitting. Very random with both. TWS light on. 4wd not engaging but 4hi light on. Small garage had replaced the front actuator, 4wd worked great. 2 months later all this electrical nonsense. Took it back to them. It sat for a few days. They test drove, no lights except TWS and 4wd worked. Then it didn't and lights came back on after about 20 miles. Took it to a dealer. Left it. They had trouble starting it. Checked the battery. A one year old NAPA had a dead cell. Napa gave me $200. The Toyota dealer replaced the battery, said all was good, no codes. I drove it away. One week later we get snow and I start plowing. No 4 wd. The 4 hi light is on but not working. Called the dealer and fortunately got the service manager. He said bring it right over and we will figure it out no charge. I get there, we chat, I tell him about all the nonsense since November when it worked fine. He said before we bring it in I want to look under the hood. Opened the engine fuse box, pointed his flashlight said I thought so. Check the picture. Mice chewed the box, wires etc. Seems Toyota uses more soy based wiring covering and plastic than petroleum based and mice love it. Insurance covering a $7900.00 main engine wiring harness and fuse box replacement. Time to mouse proof everything. My truck lives outside the garage. Wife's Volvo and my 72 Vette get the inside. Have checked them and am spraying tires with peppermint. Any other anti mice advice?

 

Picked up an 08 4x4 5.7 4door Tundra, has a P0500 code. No speedometer, ABS and BRAKE mils are on, 4hi-4lo are flashing. Also have a tire light, but no other lights. Replaced right front wheel speed sensor, it was obviously cracked and corroded, didn't fix the problem. Other sensors all visually look good, and wiring doesn't seem to be damaged. Checked the output speed sensor harness on the pass side of the transmission; it had no continuity. It has a black and yellow wire coming out of it, I tried to trace it up to where it ends, but cannot find the other end of the harness, and I don't see a yellow wire near the plug next the the fuse box, where the other front wheel speed sensor wire also ties into. Can anyone point me in the direction of where the other end of the Output VSS harness goes so that I can run some new wires? I'm assuming there's a break somewhere, or am I incorrect in assuming there should be continuity at this harness?

 

Just went through the random light flashing then all go out. 4wd won't engage but the 4 hi light comes on.
Had been to the dealer who said one cell of the battery was dead and replaced it they said all was good. one week later it snows, I am plowing but no 4 wd. Called the dealer and luckily got the service manager. Took it over right away. Told him the story. He was going to bring it right in but said lets go check something first. Check out the pics, Mice everywhere. Seems in his past he worked on auto wiring, seen the mice before.
Many wiring and plastic manufacturers for cars have changed to a soy base from a petroleum base. Mice love the soy.
The fix is to replace the wiring harness and the fuse box. Since it is connected to the engine they can't warranty it unless they do the whole thing. 17.9 hours. Have to lift the engine to get to all of it. Back ordered. Waiting for the slow boat from Japan.

 

Ends up ar ecm. Pass side of firewall. Connector is on engine side.

 

Find an independent that will go in and repair the wire. It’s tedious, but not overly difficult.

 

Sometimes it' a bad fuse. Most of the time it's mice or squirrels. Wire manufacturers use either a soy or peanut based oil in the insulation release process for the insulation of the wire.

Saw this ten years ago as a propane gas tech. I would hook up the 6 foot flex line to a gas grill, then go back a year later where the squirrels were knibbling on the gas line because it smells like peanuts.

Mothballs are the answer.

A mothball in your fuse box keeps rodents away. They hate ammonia.

Of course Ammonia off gassing does not play well with alumina tinned connections, but at least the mice won't take over your vehicle.

 

So I should have continuity there, right?

 

https://www.youtube.com/watch?v=F6l3lJwM1lU

 

Liquid heat raises a good point. P0500 is a generic obd code. You want the Toyota specific code to know whether it is one of the two trans speed sensors or one of the wheel speed sensors. Higher end code readers give the specific codes and the cheap ones just give generic codes. The wires on the two trans sensors terminate at the ecu. The wheel speed sensors terminate at the abs module.

If you pull the connector off the trans sensor and the ecu, you should get <.1 ohms between rhe pins. Will need a wiring diagram to know which pins to measure.