Regen issue and blink code help please!

36 = C1236 = Left front wheel speed sensor, waveform noisy for five seconds or more at 12 MPH or above, or noisy in sync with wheel revolutions above 6 MPH for 15 seconds or more.

42 = "Hey, there's also an ECB code."

43 = "Hey, there's also an ABS code."

45 = "Hey, there's also an ECB code."

(This is the ECB light.)

36 = "Hey, there's also an ABS code."

94 = U0073 = There was a communication error between the brake ECU and either the yaw rate/acceleration sensor or the steering angle sensor. There are six different "INF codes" that can go with this code and add to the detail; unfortunately, the blink-out-the-codes trick doesn't give the INF codes.

But you should find it easier to find the workup steps on TIS now that you know you're looking for C1236 and U0073.

 

Please, now that you've taken the smart step of getting access to the repair manual, don't diagnose that way. That's the kind of reasoning people do when they don't have access to the information.

Yes, the "brake booster with master cylinder" is going to be listed as a possibility with every trouble code, because the trouble codes come from the brake ECU, which is in that module. Diagnostically, that tells you squat. ECUs are solid-state and about the least frequent things ever to fail.

When you have the manual, use the manual. Each of the codes you have will lead to a numbered sequence of workup steps to work you methodically down to why you got that code. You don't have to guess.

 

Some multimeters will have a feature where you can ask for a beep when a reading changes. Then you can have both hands free and go to town wiggling and shaking connectors and wires to flush out an intermittent problem.

There is still a way your two codes could turn out related ... although ECUs themselves tend to go bad about as often as rocks do, electrical connections are notorious, especially when weather-exposed. Your wheel-speed sensor connections and your communication bus connections all go through that connector at the top of the brake ECU.



You might be amazed how many dead computers and other electronic devices over the years I have resurrected by doing nothing more than unplugging and reseating connectors. The newer automotive ones with the rubber seals are much much better than the open ones my 1970s cars had, but ten Boston winters is still ten Boston winters.

So you might possibly end up tracing both issues back there. (I'm not sure I would do much different in diagnosis, though, than follow the steps in the manual. Sometimes, if you have a hunch, then follow the normal steps and they lead you to your hunch, that's even better confirmation than if you just go straight there and convince yourself you've found it.)