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On automatics they use the ABS sensors for speed. The sensors on the tranny are for engine management and tranny control.

Sense bypassing the relay. Did you do so where the relay is or back at the pump? Or did you run a new power source?
 

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Discussion Starter #22
On automatics they use the ABS sensors for speed. The sensors on the tranny are for engine management and tranny control.

Sense bypassing the relay. Did you do so where the relay is or back at the pump? Or did you run a new power source?
Ok, I’ll try and troubleshoot the wheel sensor. For the relay, I bypassed the actual Fuel Pump Relay in the fuse box by the ECU.
 

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Discussion Starter #23
On automatics they use the ABS sensors for speed. The sensors on the tranny are for engine management and tranny control.

Sense bypassing the relay. Did you do so where the relay is or back at the pump? Or did you run a new power source?
alright, so I found some messed up wiring on the pass front abs, it also appeared a bit dirty. I’m going to try and patch it up tomorrow but I may just need to replace it. Sadly, these sensors are expensive as heck.
 

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You still may have a bad speed sensor at the tranny. There are two. You replaced one of them.

Good find on the ABS wiring.

Okay the bypass at the fuse box. That mean the wiring to the back of the car is good. So the issue may be in the fuse box area or the wiring from the ECU to that part of the fuse box.
 

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Discussion Starter #25
You still may have a bad speed sensor at the tranny. There are two. You replaced one of them.

Good find on the ABS wiring.

Okay the bypass at the fuse box. That mean the wiring to the back of the car is good. So the issue may be in the fuse box area or the wiring from the ECU to that part of the fuse box.
the tail end sensor seemed new-ish so I moved it to the front and the one I bought is in the back. When the wiring the the wheel was stable, and set the code in the abs unit, that’s when the vss code kicked off. After some reading, I assume that the code throwing in the abs ecu is interrupting the speed signal to the regular ecu and causing the CEL to pop. That’s my line of reasoning. I’ve ordered a new sensor and will be putting it in to see if my theory is correct.

with the relay situation, I’m going to call it a fix for now. It’s running as needed at this point. I’m wondering if the resistors that allow for the lower voltage to the FP was causing issues. With the jump, that is bypassed and it’s allowing for constant voltage.
 

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are you running techstream? ight be time to bite the bullet and pay for the diagnostic. i dont know much ,but i know from experience that codes dont always mean what they say, so yes, its possible.
 

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Discussion Starter #27
are you running techstream? ight be time to bite the bullet and pay for the diagnostic. i dont know much ,but i know from experience that codes dont always mean what they say, so yes, its possible.
regarding? I tested the front pass abs sensor and it’s showing open. So it’s bad. When I clear that code from the abs it resolves my remaining issues. I have one on order. From there, all codes will be cleared. Next up will be turning the car in to get the AC system diag’d and repaired.
 

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What did you replace them with? while scanning some of the google entries i read one of the other Lexus forums (from memory it was for an RX) which said theirs was quite sensitive to the brand and model of sensor, so they had to make sure they got the same brand as they had previously (theirs was a known good one though, yours has had that error since you got it right?).
 

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What did you replace them with? while scanning some of the google entries i read one of the other Lexus forums (from memory it was for an RX) which said theirs was quite sensitive to the brand and model of sensor, so they had to make sure they got the same brand as they had previously (theirs was a known good one though, yours has had that error since you got it right?).
I have done multiple brands on those sensors. No issues.

If you still have a fault code. You need to inspect the wiring. If it is good. It may be a problem with the reluctor in the tranny.
 

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Discussion Starter #33
I’ve been told that according to the book the signal passes through the cluster before going to ECU? If so, I may inspect that.
 

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Discussion Starter #37
I checked at the ECU plugs and the R/L is going to ground like it should. The L/Y is showing open from ecu plug pin to ground so nothing is shorted there.
 
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