[no_common_sense]

I hate to keep kicking a dead scan tool here, but when you say full scan, how full is a full scan to you? And when you say ECS, do you mean ECM as in engine control module? Or does ECS refer to electronic stability control? ECS is a new one to me. Did I miss altogether?

The reason I ask, is because when I read full scan, I'm expecting that to mean absolutely every module was checked for codes. I'd not only look at modules turning lights on, but also the ECM, the BCM, and even the instrument panel cluster. I'd be looking for lost communication codes in any and all modules as a start. That or circuit open/shorted codes.

With or without a scan tool, I'd want to look at wiring harnesses anywhere I can find them in the engine bay. See what you can under the dash, and look for any evidence of wiring damage. Rub throughs near sharp edges & corners, green crusty oxidations, burnt wiring, rodent dining, etc... If the car has a known accident history, pay attention to places where the body shop may have been working near harnesses.

One last sneaky thing I can think to try is pulling fuses, one at a time, for the ABS module and the instrument cluster. Pull a fuse and go for a test drive, see if/what changes. If no change, plug that fuse back in and pull the other; wash, rinse, repeat. It might not work for the cluster though. Depending on the factory installed bells & whistles, anti theft might need the cluster alive to even start the car. Keep in mind, this is only something to do after you absolutely know there are no codes to chase. Once you start pulling fuses, you introduce codes, and they don't need to be mistaken for actual problems. If, by chance, pulling the ABS or cluster fuse does restore normal shifting, you can start looking at that module and it's wiring as a root problem.

 

[no_common_sense]

One piece of new information. I disconnected ABS module and started car. Still have ABS and Brake light, no CEL, however speedometer no reads ZERO instead of 10 MPH.

That looks interesting. Assuming you just disconnected the module electrically, I'd go for that test drive as is.

 

[no_common_sense]

I can't tell you if it would need a reflash, but I'm 90% on board with trying another ABS module regardless. I'm still a stickler for a certain amount of circuit testing before spending any money on anything on eBay. California car or not, powers, grounds, and communication circuits should always be tested before firing the parts cannon. Voltage drop testing is what I always recommend. I have little use for Ohm meters as they never test a circuit under live, loaded conditions. I would even settle for simple testing with a test light. That's for basic powers and grounds, though. Communication circuits need a scope to see a waveform. Do a visual inspection on the pins & terminals of the connector at the ABS module, too. Look for all the other stuff I recommended in my previous post no matter how California your car is.

One last thing you might be able to try on your own is to disconnect wheel speed sensors at each wheel and see if the speedometer settles back down. Reconnect the ABS module to the harness. Disconnect one wheel speed sensor at a time and reconnect if the speedometer stays stuck at 10 MPH. If you disconnect one and find the speedometer back at zero, leave that sensor disconnected and go for a test drive with everything else reconnected. If you regain normal driving AND your speedometer, that speed sensor you disconnected is shorted. It won't shut off the ABS light as you just created a new code by leaving a sensor disconnected. The ABS module can at least send valid wheel speed data to the cluster from the other three sensors.

There's always a chance that's an excercise in chasing your tail. I'd then, at least, look for the other end of the speed sensor connectors to have what's called a bias voltage. I can't provide any specs, but you can always use a little Sesame Street logic. Test for voltage across all four connectors; see if one of these things is not like the others. They may not have the same voltage across all four connectors. They should at least be the same from side to side. That assumes Toyota does run a bias voltage on the sensor circuits to detect opens. I'd also test the sensor wires going back to the module. This would be an OK place for an Ohm meter. Just test at each wheel speed sensor connector for unwanted continuity to ground.

After that, if you want to fire another module at it, it's not a terrible gamble. But eBay does make it more of a gamble. You're buying a used part that might also be a faulty part. Finding bad parts and trying to fix them with more bad parts makes you second guess yourself into unbridled confusion. The best I can recommend is that you look at the seller history for good feedback and see if used car parts are what the guy primarily sells. Outside of eBay, I'll let you do your own Googling on Toyota ABS module pattern failures. Try to find some valid concensus that ABS modules are a pattern failure part.

Having said that, can any owners of older Camrys on this forum speak to any repair history on their own cars that point at ABS module replacements?

 

[no_common_sense]

But that doesn't explain the lack of codes from the two fancy scanners.

It happens more than you'd think. I'm happy for you that you've at least got a reasonable direction in your diagnosis.

 

[no_common_sense]

Don't thank us just yet. The bill is in the mail...😁

But seriously, I'm happy to hear you won.