My son was driving around town yesterday, and the car entered fail safe mode (all warning lights turned on), the speedometer reads "0" at all times, and "Check Hybrid System" shows in the display. Other than that, the car seems to run fine. I ordered a VCI cable and hooked it up today. I get multiple systems throwing a U0129 error. -- Hybrid control system - u0129 - 220, 527, 528 -- Cruise control - u0129 -- pm2 gateway - u0129 -- emps - u0129 -- power source control - u0129 The U0129 errors are all described as "Lost Communications with Brake System Control Module" except for Power Source Control which describes it as "Vehicle Speed Signal Communication". Also, when I click on the magnifying glass on the hybrid control error, it says do not diagnose. But when I click on the magnifying glass on emps, pm2, and power source control, they all say "Malfunction is present". I've tried clearing the errors multiple times, but they always come back within a few seconds. Anyone have any ideas as to what might be happening or what I might try? I'm hoping that it might be something simple like a loose connection or a relay/fuse. I consider myself reasonably handy. I change the oil myself, and replaced the spark plugs, but am certainly no mechanic or technician. The car is a 2011 and has 215,000 miles on it, so I certainly hope this isn't something the dealer will want to charge thousands for. Thanks!
As I read, it has to do with a no- signal error from the brake cylinder solenoid. My suggestion would be to: 1 Check fuses 2 test circuits for powers and grounds 3 check any connectors for corrosion
Thanks. Looking at the results a little closer, I'm not getting any communication from the ABS/VSC/TRAC system. I checked the fuses, and removed the cowling or whatever you call it to check the skid control ecu connector and they look fine. I'll take it to the mechanic and have him look at it. I'm still hoping they will find a frayed wire or something, but with my luck I'll need a new Brake booster with master cylinder.
Well, I got the Brake booster / master cylinder replaced, after which there were still a short somewhere. The mechanic ran down the short and bypassed it. At the end, I'm not sure what the real problem was, but it is working now.
Hello. You pointed out that the mechanic ran it down and found a short and bypassed it. Did he say where the short was at or did he provide any additional information? Can you ask the mechanic for additional information? Thank you,
