Toyota Tacoma (2015-2018) Service Manual: Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129)
DESCRIPTION
The millimeter wave radar sensor assembly and ECM communicate with each sensor and ECU via CAN communication.
If any malfunction is detected in a CAN communication circuit, one or more CAN communication system DTCs are stored.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
MIL |
|---|---|---|---|---|
|
U0100 |
Lost Communication with ECM / PCM "A" |
While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the ECM and the millimeter wave radar sensor assembly is detected for approximately 1 second or more. |
|
Does not come on |
|
U0125 |
Lost Communication with Yaw Rate Sensor Module |
While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the yaw rate sensor and the millimeter wave radar sensor assembly is detected for approximately 1 second or more. |
|
Does not come on |
|
U0126 |
Lost Communication with Steering Angle Sensor Module |
While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the steering angle sensor and the millimeter wave radar sensor assembly is detected for approximately 1 second or more. |
|
Does not come on |
|
U0129 |
Lost Communication with Brake System Control Module |
While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 and the millimeter wave radar sensor assembly is detected for approximately 2.5 seconds or more. |
|
Does not come on |
- *1: for Hydraulic Brake Booster
- *2: for Vacuum Brake Booster
PROCEDURE
|
1. |
CHECK FOR DTCs (RADAR CRUISE 1 AND RADAR CRUISE 2) |
(a) Clear the DTCs.
Click here .gif)
(b) Make sure that the DTC detection conditions are met.
HINT:
If the detection conditions are not met, the system cannot detect the malfunction.
- Turn the ignition switch to ON.
- Turn the dynamic radar cruise control system on using the cruise control main switch (ON-OFF button).
- Drive the vehicle at 36 km/h (22 mph) or more for 5 seconds or more.
(c) Check for DTCs.
Click here
|
Result |
Proceed to |
|---|---|
|
DTC U0100, U0125, U0126 and U0129 are not output |
A |
|
DTC U0100, U0125, U0126 or U0129 is output |
B |
| A | .gif) |
USE SIMULATION METHOD TO CHECK |
| B | |
GO TO CAN COMMUNICATION SYSTEM |
Communication Error from ECM to VSC Invalid Serial Data Received (P163181)
DESCRIPTION
The ECM sends signals such as dynamic radar cruise control operation signals,
brake operation demand signals and buzzer operation demand signals to the skid control
ECU (master cylind ...
Lost Communication With ECM/PCM "A" Missing Message (U010087,U010487,U012287)
DESCRIPTION
The ECM communicates with each sensor and ECU via CAN communication.
If any malfunction is detected in a CAN communication circuit, one or more CAN
communication system DTCs are stored ...
Other materials:
Open or Short in Front Speed Sensor RH Circuit (C1405,C1406)
DESCRIPTION
Refer to DTCs C1401 and C1402 (See page ).
DTC No.
Detection Item
DTC Detection Condition
Trouble Area
C1405
Open or Short in Front Speed Sensor RH Circuit
Either of the following is detected:
...
Lost Communication with ECM / PCM "A" (U0100,U0126,U0129,U0142)
DESCRIPTION
These DTCs are stored if there is a malfunction in the CAN communication system
connected to the blind spot monitor sensor.
HINT:
If CAN communication system DTCs are stored, they may also be stored for other
systems.
DTC Code
DTC Detection Condition
...
Abbreviations Used In Manual
ABBREVIATIONS USED IN MANUAL
Abbreviations
Meaning
ABS
Anti-Lock Brake System
A/C
Air Conditioner
AC
Alternating Current
ACC
Accessory
ACIS
...
