Toyota Tacoma 2015-2018 Service Manual: Lost Communication With Vehicle Dynamics Control Module (U0122)

Toyota Tacoma 2015-2018 Service Manual / Differential / Differential System(w/ Rear Differential Lock) / Lost Communication With Vehicle Dynamics Control Module (U0122)

DESCRIPTION

This DTC is detected if communication is lost with the skid control ECU (brake actuator assembly).

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
U0122	Lost Communication with Vehicle Dynamics Control Module	Diagnosis Condition: Ignition switch turned to ON (3 seconds elapse after ignition switch is turned to ON) Malfunction Status: Communication is lost between skid control ECU and 4 wheel drive control ECU Malfunction Time: 0.72 seconds or more Other: 1 trip detection logic	CAN communication system

CAUTION / NOTICE / HINT

HINT:

for 4WD:
When the data in the skid control ECU (brake actuator assembly) is being overwritten, a message is displayed on the multi-information display and the 4LO indicator light rapidly blinks due to the 4 wheel drive control ECU detecting a communication malfunction (blinks at 0.25 second intervals (0.25 seconds on and 0.25 seconds off)), but this is not a malfunction.

for 2WD:

When the data in the skid control ECU (brake actuator assembly) is being overwritten, the rear differential lock indicator light may rapidly blink due to the 4 wheel drive control ECU detecting a communication malfunction (blinks at 0.25 second intervals (0.25 seconds on and 0.25 seconds off)), but this is not a malfunction.
Clear all DTCs, since DTCs are stored after the data in the skid control ECU (brake actuator assembly) is overwritten.

PROCEDURE

1.	PERFORM DTC

(a) Clear the DTCs (See page (b) Check if the same DTCs are output (See page ).

(b) Check if the same DTCs are output (See page Result ).

Result

Result	Proceed to
DTC is output	A
DTC is not output	B

CHECK CAN COMMUNICATION SYSTEM

USE SIMULATION METHOD TO CHECK

Lock Switch Circuit

WIRING DIAGRAM PROCEDURE 1. CHECK REAR DIFFERENTIAL LOCK INDICATOR LIGHT (a) Turn the ignition switch to ON. (b) for 4WD: Finish switching to L4. (c) Check the ...

Differential System(w/o Differential Lock)

Precaution PRECAUTION 1. Before disassembly, clean the outside of the front and rear differential assembly and remove any sand and mud to prevent it from entering the assembly during disassembly ...

Other materials:

Removal
REMOVAL CAUTION / NOTICE / HINT NOTICE: Release the vacuum from booster by depressing the brake pedal several times. Then remove the brake master cylinder from brake booster. PROCEDURE 1. PRECAUTION NOTICE: After turning the ignition switch off, waiting time may be required before disconnect ...

On-vehicle Inspection
ON-VEHICLE INSPECTION PROCEDURE 1. CHECK FUEL PUMP OPERATION AND INSPECT FOR FUEL LEAK (a) Connect the Techstream to the DLC3. (1) Turn the ignition switch to ON. NOTICE: Do not start the engine. (2) Turn the Techstream on. (3) Enter the following menus: Powertrain / Engine / Active Test / C ...

How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT HINT: Use these procedures to troubleshoot the smart key system (for Start Function). *: Use the Techstream. PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP NEXT ...