Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Bus Buffer ECU Communication Stop Mode [11/2018 - 02/2019]: Procedure
- CHECK OPTIONS
- Check whether dealer installed options that support CAN communication are installed.
Result
Result Proceed to Installed A Not installed B
Result:
B
See step 3
Result:
A
See step 2
- Check whether dealer installed options that support CAN communication are installed.
- CHECK FOR OPEN IN CAN BUS WIRE (OPTION CONNECTOR [BUS BUFFER ECU] BRANCH WIRE)
- Disconnect the cable from the negative (-) auxiliary battery terminal.
- Disconnect the option connector (bus buffer ECU).*
*a Front view of wire harness connector
(to Option Connector [Bus Buffer ECU])*: When a dealer-installed option is installed
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition G80-2 (CAN+) - G80-1 (CAN-) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω Result
Proceed to OK NG
Result:
OK
CHECK DEALER-INSTALLED OPTION
Result:
NG
REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR
- CHECK FOR OPEN IN CAN BUS WIRE (OPTION CONNECTOR [BUS BUFFER ECU] BRANCH WIRE)
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Body Electrical / Central Gateway / Utility / Initialization.
Body Electrical > Central Gateway > Utility
Tester Display Initialization - Enter the following menus: Body Electrical / Main Body / Utility / Initialization.
Body Electrical > Main Body > Utility
Tester Display Initialization - Enter the following menus: Body Electrical / Main Body / Clear DTCs.
Body Electrical > Main Body > Clear DTCs
- Enter the following menus: Body Electrical / Main Body / Trouble Codes.
Body Electrical > Main Body > Trouble Codes
Result
Result Proceed to DTC U1117 is not output from main body ECU (multiplex network body ECU) A DTC U1117 is output from main body ECU (multiplex network body ECU) B
Result:
A
END
Result:
B
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)
Refer to REMOVAL [11/2018 - 02/2019]
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.