Brake, ABS, VCS and ! Lights = Main Computer

DTC C0210 refers to the right rear speed sensor. The possible trouble areas include:

Right rear and left rear speed sensor

Each speed sensor circuit

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Sensor rotor

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Sensor installation
Skid control ECU

The skid control ECU is not covered under the hybrid vehicle warranty, and in any event that warranty expired at 100K miles.

I hope that you've already checked to ensure that the four tires are of the same size and have similar tread depth; and that they are all inflated to the same tire pressure.

It is not typical for any ECU to fail, but it is not impossible for this to happen. You may want to inquire into the possibility of purchasing a used ECU from a salvage vehicle, which may cost $400 or so. Good luck.




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Hi Dalena,

ECU: electronic control unit. ECU is aka "computer".

$300 represents ~3 hours of labor time, which seems a bit high but not improbable.

It certainly is reasonable for you to seek another opinion.

 

Take it somewhere else, particularly a place that would be willing to install a salvage skid ECU. It is odd that they would not just replace the speed sensor (a common failure) and reset the codes, though. FYI, intermittent problems often lead to a "replace computer" diagnosis. If they are going to make you pay $300 in order to get your car back, insist on a full print-out of the freeze frame data, and post here.

 

The repair manual suggests using an oscilloscope to verify the sensor's proper operation while the car is traveling at 19 mph speed. If the tech actually did that, then that would be a reasonable check.

You may want to ask how the tech checked the sensor. If an oscilloscope was not used, it would be reasonable to replace the sensor and see what happens.

Also note that the left sensor is also a suspect part, so that part's functioning also should be checked.

The diagnostic printout doesn't really provide more useful info beyond the DTC that you had already posted.

 

This freeze frame data shows 0 MPH shown by all wheel sensors. That casts some doubt on the "off by 1 MPH" argument, but otherwise this is a puzzle.

 

Okay, I have a rant. The attached picture shows the service manual outcome for testing the waveform of wheel speed sensors. OK -> Replace Skid ECU, NG -> Replace Skid ECU. Are you F*****G kidding me???

 

My rant is a mistake in the service manual. If the test is No Good (NG), then the next step should be inspect speed sensor, tone ring, connections, rather than replace ECU!

Anyway, a salvage ECU is $100 +/-. If you get to that point, it needs to be installed by someone that has a Toyota-specific scan tool so as to set zero point calibrations and initialize the linear solenoid valve.

 

WoooHooo!!!

I did contact Toyota about the error in the service manual.

 

Funny isn't it? An older version of the repair manual had it correctly:

Maybe the guy that was hired to do copying and pasting fell asleep.

Glad to know it was just something got loose.

Yes let us know when they correct it - wonder how long it will take.

 

I would be interested to know whether you went back to the Service Manager at Toyota Dealer #1 to complain about their eagerness to charge you $2300 for a repair that was not needed, and his reaction!

 

If your repair invoice from dealer #2 is not very clear about what was loose, perhaps you might ask about that.

If the skid control ECU fails, then you will find that it is extremely hard to stop the car. This may not be "go out completely" but it will be scary if you are not able to exert tremendous force on the brake pedal.

 

Damn, I thought they had it licked. But definitely go back to place #2. If they have any pride and customer service focus, they should either fix yours right, or leave you with a definitive diagnosis. It still seems like a bad connection somewhere, though. Does the light come on when you start up the car? Or is it while you are driving?

The main requirement for the independent shop is that they are able to program the new ECU using Toyota Techstream or equivalent. There are several independent shops in Oregon listed here: Preferred Independent Hybrid Car Repair and Service Shops | Hybrid Cars

Pat, even if the skid ecu fails completely, there should be enough pressure in the hydraulic system for one or two assisted stops, no? I can't believe all the extra trouble they went to with the multiple failsafes, e.g. capacitor backup power, would be voided out by a sudden failure.

 

I don't have personal experience with this. When my dad owned the 2007, this happened to him a couple of times. He told me that the Prius was very hard to stop.

Did he use up his "one or two assisted stops" with gentle brake pedal application, before realizing that he needed to get serious about stopping the car and only had a couple of chances to do that? Or did the system offer no help to begin with? Hard to say.

 

I have had this happen, and it is extremly difficult to stop the car. Also, an audiable alarm sounds. IT is only safe to drive very slowly with lots of room in front of you.