Toyota Tacoma (2015-2018) Service Manual: Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129)

Toyota Tacoma (2015-2018) Service Manual / Pre-collision / Pre-collision System / Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129)

DESCRIPTION

These DTCs are stored when a communication malfunction occurs between ECUs that perform pre-collision system control.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
U0100	Lost Communication with ECM / PCM "A"	When the vehicle is being driven at a speed of 5 km/h (4 mph) or more, a communication error between the ECM and millimeter wave radar sensor assembly is detected for approximately 4 seconds.	CAN communication system ECM Millimeter wave radar sensor assembly
U0125	Lost Communication with Yaw Rate Sensor Module	When the vehicle is being driven at a speed of 5 km/h (4 mph) or more, a communication error between the yaw rate sensor (airbag sensor assembly) and millimeter wave radar sensor assembly is detected for approximately 1 second.	CAN communication system Yaw rate sensor (Airbag sensor assembly) Millimeter wave radar sensor assembly
U0126	Lost Communication with Steering Angle Sensor Module	When the ignition switch is ON, a communication error between the steering angle sensor (spiral cable with sensor sub-assembly) and millimeter wave radar sensor assembly is detected for approximately 1 second.	CAN communication system Steering angle sensor (spiral cable with sensor sub-assembly) Millimeter wave radar sensor assembly
U0129	Lost Communication with Brake System Control Module	When the ignition switch is ON, a communication error between the skid control ECU (master cylinder solenoid)1 or skid control ECU (brake actuator assembly)2 and millimeter wave radar sensor assembly is detected for approximately 6 seconds.	CAN communication system Skid control ECU (master cylinder solenoid)1 or skid control ECU (brake actuator assembly)2 Millimeter wave radar sensor assembly

*1: for Hydraulic Brake Booster
*2: for Vacuum Brake Booster

PROCEDURE

1.	CHECK FOR DTCs (PRE-COLLISION 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 detection conditions are not met, the system cannot detect the malfunction.

Click here

Result	Proceed to
DTC U0100, U0125, U0126 and U0129 are not output	A
DTC U0100, U0125, U0126 or U0129 is output	B

USE SIMULATION METHOD TO CHECK

GO TO CAN COMMUNICATION SYSTEM

Heater Circuit (C1AAE)

DESCRIPTION If the forward recognition camera detects a malfunction in the camera heater (forward recognition hood) circuit, it will output a malfunction signal to the millimeter wave radar senso ...

Lost Communication with Cruise Control Front Distance Range Sensor (U0235)

DESCRIPTION The millimeter wave radar sensor assembly is connected to the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 via CAN communication. If c ...

Other materials:

Mechanical System Tests
MECHANICAL SYSTEM TESTS 1. STALL SPEED TEST HINT: This test is to check the overall performance of the engine and transmission. CAUTION: This test should be done on a paved surface (a surface that is not slippery). To ensure safety, perform this test in an open and level area tha ...

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 and installation. 2. When removing connected parts made of a light alloy, such as front and rear ...

Check For Intermittent Problems
CHECK FOR INTERMITTENT PROBLEMS 1. DESCRIPTION HINT: A momentary interruption (open circuit) in the connectors and/or wire harness between the sensors and ECUs can be detected through the ECU data monitor function of the Techstream. (a) Turn the ignition switch off. (b) Connect the Techstre ...