Hi,
I have a 2007 IS 350 with 122,000 miles. the VSC, ABS warning light have coming on. In the past I just open and closed the gas cap and the light went off. So I went an bought a new gas cap. That worked for three weeks. The lights have come on again and the little trick hasn't worked. Brought it to a mechanic and Code C1203 came up; Electronic Control Module Communications Circuit Malfunction. Has this happen to anyone else? This sounds like an expensive fix. The car is running great.

 

This isn't for a IS 350 but it is for a Toyota so it stands to reason that it is representative of the problem you are having.

http://share.qclt.com/%E4%B8%B0%E7%9...em/0370017.pdf

Anyway, you look at it, it will be expensive to fix. Worst case a new ECM for c1203.

 

Thank you, I'll check it out.

 

dont know if you got this fixed, but i just fixed this on my is350. reset the VSC by doing the Zero Point Calibration. A quick search on will yield you the info.

 

I know it's been a few years, but just thought I'd mention since this post shows up when Googling these exact keywords. On my 2015 IS250 I also got the "Check ABS" warning and the "VCS Off" symbol as well as ABS Code C1203 DTC - ECM Communication Circuit. This was after changing all brake pads and rotors while having the car fully on jack stands. We think this happened because I messed with the transmission shifts while wheels were off ground. Which is something you should never do with cars like these, and my bonehead self found the hard way.

None of the DIY Zero Point Calibration tricks on Youtube worked for me, maybe I did them wrong or the ones I found weren't meant for this car. I took it to my local Mechanic who was able to calibrate with his Snap-On scan tool easy within 20 minutes, of course that didn't come free lol!

 

I had luck here on zero point.
https://www.clublexus.com/forums/is-...l#post10248684