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:

ECM Communication Circuit Malfunction (C1203)
DESCRIPTION The circuit is used to send TRAC and VSC control information from the skid control ECU (brake actuator assembly) to the ECM, and engine control information from the ECM to the skid control ECU (brake actuator assembly) through the CAN communication system. for 4WD or w/ Rear Diff ...

Installation
INSTALLATION CAUTION / NOTICE / HINT HINT: Use the same procedure for both the LH and RH sides. The procedure described below is for the LH side. PROCEDURE 1. INSTALL HEADLIGHT ASSEMBLY (a) Connect the connectors. (b) Engage the clamp to install the headlight assembly. (c) ...

Data List / Active Test
DATA LIST / ACTIVE TEST 1. DATA LIST HINT: Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals ...