U0129
Lost Communication With Brake System Control Module
DTC U0129, sometimes indicated as U012900 is an OBD diagnostic trouble code indicating a generic fault with the vehicle user network.
- U0129: Lost Communication With Brake System Control Module
- U0129: Data bus, brake system control module – no communication
- U0129 00: Data bus, brake system control module - no communication
See Also: Related Error Codes
Bulletins are notices put out by manufacturers in conjunction with the NHTSA to notify the public of manufacturing issues or changes.
- TSB-0325-08 - SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:ABS WARNING LIGHT
TOYOTA: Toyota vehicle: abs, brake, or 4wd mil "on". If the abs, brake, 4wd, and/or "check engine" light is "on" due to dtcs U0129 and P0500, replace the brake actuator assembly. *pe
2017 HONDA CR-V with 60000.0 miles
On 1/8/20 when i started my car in the morning all warning lights came on before leaving the driveway, and stayed on all the way to work, and back. Then again the following morning. I called Honda on 1/9/20, they advised to come in sooner than later. Car is at Honda now 1/10/20, they are stating all codes may be due to two codes that need to be fixed: P0302 (fuel injection), which is covered under warranty and U0129 lost communication with braking system due to a/c control unit - which will cost me $1630 for a car with only 60,000 miles on it! Of note: the car's emergency brake while driving has triggered a couple of times, and all warning lights have come on before in heavy rain.
ELECTRONIC STABILITY CONTROL, FUEL/PROPULSION SYSTEM UNKNOWN OR OTHER
2017 TOYOTA COROLLA with 13192.0 miles
Red brake light, abs, vsc, power steering, and mil lights came on. Dtc's U0129.
SERVICE BRAKES, ELECTRONIC STABILITY CONTROL VEHICLE SPEED CONTROL FUEL/PROPULSION SYSTEM UNKNOWN OR OTHER ELECTRONIC STABILITY CONTROL
2011 TOYOTA CAMRY with 5000.0 miles
Driver first noticed a problem when she came to a stop at a traffic light. The Camry started revving the engine even though driver was depressing the brake pedal; at this point the traction light came on. Five minutes later, driver approached a red light going approximately 25 mph. She depressed the brake pedal and the Camry made a loud sound then jerked forward repeatedly. The brakes did not slow down the car consequently causing her to run the red light. She then attempted to get to a safe place, so she pulled into a parking lot. When driver attempted to stop by depressing the brake pedal all the way to the floor, the car did not stop or slow down nearly causing her to crash into a parking lot barrier. There was a noticeable burning smell. Terrified, we took the Camry to a Toyota dealership. The dealership technicians recovered diagnostic trouble codes: C1249 and U0129. The technicians also drove the Camry for 55 miles, but they did not make any repairs, despite the dtc codes, because they said they could not replicate the problem. This is a brand new Camry, and we are terrified to drive it, but Toyota won't do anything about it because they say there's nothing wrong. The diagnostic trouble codes indicate otherwise. Based on research we did, the first code C1249, indicates an opening in the stop light switch circuit, which recommends three likely causes of the error, 1) the stop light switch, 2) stop light switch circuit, or 3) the brake actuator assembly (skid control ecu). The second code U0129 indicates trouble with the abs and traction actuator assembly (as well as the skid control ecu), or the can communication system. This is particularly alarming because what this error means is that the computer disengages the brakes, which is clearly what happened to us. The Toyota dealership told us to contact corporate; corporate told us to contact the dealership. No repairs have been done, and the car is just collecting dust now.
SERVICE BRAKES, ELECTRIC,