Toyota Tacoma (2015-2018) Service Manual: Lost Communication with ECM / PCM "A" (U0100,U0101,U0123,U0126,U0129,U0142,U0155)

Toyota Tacoma (2015-2018) Service Manual / Cruise Control / Forward Recognition Camera System / Lost Communication with ECM / PCM "A" (U0100,U0101,U0123,U0126,U0129,U0142,U0155)

DESCRIPTION

When a malfunction is detected between various ECUs and sensors, these DTCs are stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
U0100	Lost Communication with ECM / PCM "A"	After the ignition switch is turned to ON for 3 seconds or more, when the vehicle is being driven at a speed of 1 km/h or 1 mph or more, a communication error between the ECM and forward recognition camera is detected for approximately 5 seconds or more.	CAN communication system ECM Forward recognition camera
U0101	Lost Communication with TCM	After the ignition switch is turned to ON for 3 seconds or more, when the vehicle is being driven at a speed of 1 km/h or 1 mph or more, a communication error between the TCM (ECM) and forward recognition camera is detected for approximately 5 seconds or more.	CAN communication system TCM (ECM) Forward recognition camera
U0123	Lost Communication with Yaw Rate Sensor Module	After the ignition switch is turned to ON for 3 seconds or more, when the vehicle is being driven at a speed of 1 km/h or 1 mph or more, a communication error between the yaw rate and acceleration sensor (airbag sensor assembly) and forward recognition camera is detected for approximately 5 seconds or more.	CAN communication system Yaw rate and acceleration sensor (airbag sensor assembly) Forward recognition camera
U0126	Lost Communication with Steering Angle Sensor Module	3 seconds after the ignition switch is turned to ON, a communication error between the spiral cable with sensor sub-assembly and the forward recognition camera is detected for approximately 5 seconds or more.	CAN communication system Spiral cable with sensor sub-assembly Forward recognition camera
U0129	Lost Communication with Brake System Control Module	3 seconds after the ignition switch is turned to ON, a communication error between the skid control ECU (brake actuator assembly) and the forward recognition camera is detected for approximately 5 seconds or more.	CAN communication system Skid control ECU (brake actuator assembly) Forward recognition camera
U0142	Lost Communication with Body Control Module "B"	3 seconds after the ignition switch is turned to ON, a communication error between the main body ECU (multiplex network body ECU) and the forward recognition camera is detected for approximately 5 seconds or more.	CAN communication system Main body ECU (multiplex network body ECU) Forward recognition camera
U0155	Lost Communication with Combination Meter	3 seconds after the ignition switch is turned to ON, a communication error between the combination meter assembly and the forward recognition camera is detected for approximately 50 seconds or more.	CAN communication system Combination meter assembly Forward recognition camera

PROCEDURE

1.	CHECK FOR DTCs (FORWARD RECOGNITION CAMERA SYSTEM)

(a) Clear the DTCs.

Click here (b) Make sure that the DTC detection conditions are met.

(b) Make sure that the DTC detection conditions are met.

HINT:

If the conditions are not met, the system cannot detect the malfunction.

Click here

Result	Proceed to
DTC U0100, U0101, U0123, U0126, U0129, U0142 or U0155 are not output	A
DTC U0100, U0101, U0123, U0126, U0129, U0142 or U0155 is output	B

USE SIMULATION METHOD TO CHECK

GO TO CAN COMMUNICATION SYSTEM

Diagnostic Trouble Code Chart

DIAGNOSTIC TROUBLE CODE CHART Forward Recognition Camera System DTC No. Detection Item Link C1A0A Front Radar Sensor Region Code Mismatch ...

Yaw Rate Sensor Circuit (C1AA4,C1AA5)

DESCRIPTION The forward recognition camera receives vehicle stability signals from the yaw rate and acceleration sensor (airbag sensor assembly). If the yaw rate and acceleration sensor (airbag s ...

Other materials:

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 ...

Vehicle Speed Sensor Circuit (C1AA3)
DESCRIPTION The forward recognition camera receives vehicle speed signals from the skid control ECU. If the skid control ECU receives a vehicle speed sensor malfunction signal, it informs the forward recognition camera via CAN communication, and DTC C1AA3 is stored. DTC No. ...

Dtc Check / Clear
DTC CHECK / CLEAR NOTICE: When the diagnosis system is changed from normal mode to check mode or vice versa, all DTCs and freeze frame data recorded in normal mode are cleared. Before changing modes, always check and make a note of DTCs and freeze frame data. HINT: DTCs which are sto ...