tytho

My 2012 RX450h brake warning light came on recently (the one that looks like this (!) ) and the error message on the dash says "CHECK BRAKE SYSTEM" shortly after starting the car. The warning light seemed to start coming on after I had to hard brake to avoid hitting a car backing out of a parking spot.

I was able to read the DTC code being reported: C1377 - Capacitor. I believe this code refers to the Brake Control Power Supply Module. The Freeze Frame detailed DTC subcode is 105 (the number under the column labeled "0"). Does anyone know what that subcode refers to?

Anyone else have this error code come up on their RX? Any advice on how to further diagnose or fix this?

Thanks.

Clutchless

Go to a repair shop that specializes in Toyotas as they should have Techstream to run a complete diagnosis and conduct more detailed troubleshooting analysis. When was the brake fluid last flushed?

tytho

@Clutchless - Thanks for the suggestion, but I had a friend who had one of those mini-VCI cables that came with Techstream from ebay and we extracted the DTC code C-1377. The freeze frame page showed what I believe is the subcode of 105, but haven't been able to figure out what that may indicate. Beyond that, haven't troubleshooted beyond that.

I'm not sure when the brake fluid was last flushed as I bought the car used, so I know it hasn't been flushed in the time I've owned the car (little over 3 years).

Clutchless

It should be done every 2 or 3 years and is often neglected. Brake fluid absorbs moisture and bad brake fluid can cause internal corrosion and failure of expensive brake system components such as the electronic brake force distribution module, ABS etc. Get it done by a shop that has TEchstream and can activate ABS etc and do a proper full system flush, then maybe clear the codes and hope all is well afterwards!

Try some searching and read the sticky threads at https://www.toyotanation.com/forum/1...ion-2008-2013/

The 2nd gen Highlander is a mechanical twin to the RX350. Maybe they have more information as more of them work on their own vehicles.