Wheel speed sensor no ground signal

2016 Tacoma, code C1407



Checked other threads but problem is upstream.



Initially changed RR speed sensor to no avail. Checked for signal and have + but no -. Checked S22 and still no negative for RR. FSM next advises to check pin S1-45S to S22-3. where is connector S1 located? Is the speed sensor ECU the same as the ECU behind the glove box?



all suggestions welcome.

 

S1 is directly on the ABS module, so either passenger engine bay rear or drivers engine bay brake booster(Offroad only).

Disconnect it and probe carefully.

Typically rear ABS codes on Tacoma's are caused by the rear axle harness which is easier to probe and more likely of a failing point. S22 is simply above the rear axle, follow the harness up.

 

Thanks, problem seems to be upstream of S22 as no negative at this connection.

 

How are you testing? The "-" in this scenario is simply polarity of the sensor, not vehicle ground.

Checking continuity from one end to another is the simplest way to check.

The idea is that the rear axle harness is always moving and exposed to more elements than upstream would.

 

RL- crossed with RR +

And RL+ with RR-

To check voltage


At pigtail harness
RR- & RR+ no voltage
RL- & RL+ 10.2V
RR- & RL+ no voltage
RR+ & RL- 10.2v

 

Does the original post have 100k pixels of empty space for anyone else than me?

 

OP broke the internet for sure

 

yes...its a mile down to the first post..i had to put it in 4 wheel drive to get down here

 

Okay, wasn't sure if content was loading.

 

OP must have edited it. It was about 27 miles long earlier.

 

Speed sensors are signal generators. Resistance is more important than voltage. I would check resistance along the length of each leg. Start at the ECU plug, pins 44 & 46. If you get the correct resistance listed then start shaking the harness until you don't.

 

Then, if you don't get the resistance, start ohming out each leg of the harness for an open. The chart you supplied provides all the information. And just to note... does not look for voltage.

 

This is one hell of an inbred thread lol

 

This thread is not Ohming

 

After a number of attempts I think I got the corrupt dead space out of the OP. However still trying to resolve speed sensor wiring.

 

I just resolved mine. However mine was for the front left. Mine is a 2.7 not a v6. But judging by the wiring harnesses and having to have tracked shit down for the past month the skid control(abs, stability control) harness is separate from the engine management so it should be the same possibly. Maybe someone can confirm. It’s worth taking a large section apart because it makes it easier, the sensor wires are also twisted together to cancel interference/noise so they should be easy to pick out.. you’ll also have to take large sections apart because beneath the electrical tape is a hard plastic cover. This is assuming this is where your issue is. I’ve Never touched my wiring harness, but it almost looks like it was nicked/cut then it stretched out. I didn’t use anything sharp so I don’t know… anyways good luck!

 

Well we had a very successful day fixing the sons Tacoma. I flew out from Alberta to BC to help him troubleshoot a number of faults. We pulled the box off as we had to do the rubber grommet insert anyway. One bolt wouldn't budge and we sheared the teeth in the bolt head so drilled the head off. Upon pulling off the box we drove the tacoma out into the dark to power wash. Once clean we had a look at the wire harness and even in the dark we immediately and visually saw the damage to the wire just upstream of S22; most likely from the shifting box. We opened up the sheathing and found the yellow RH - was only held by its insulation. A quick splice and all fault codes disappeared. Now we can move on to the small stuff.