Vehicle Interior

Lost Communication with ECM / PCM (U0100,U0129,U0142,U0155)

~1min read
DESCRIPTION

The power management control ECU receives information from 2 sources. It receives information via a direct line and via the CAN communication line. If the information from these 2 sources is inconsistent, this DTC is stored.

HINT:

When the power management control ECU is replaced with a new one and the cable is connected to the negative (-) battery terminal, the power source mode is reset to on (IG). When the battery is removed and reinstalled, the power source mode that was selected when the battery was removed is restored.

DTC Code

DTC Detection Condition

Trouble Area

U0100

There is no communication from the ECM.

  • CAN communication system
  • ECM

U0142

There is no communication from the main body ECU.

  • CAN communication system
  • Main body ECU (Driver side junction block assembly)

U0129

There is no communication from the skid control ECU.

  • CAN communication system
  • Skid control ECU

U0155

There is no communication from the combination meter.

  • CAN communication system
  • Combination meter assembly
PROCEDURE
  1. CHECK FOR DTC

(a) Check for DTCs and note any codes that are output (See page ).


(b) Clear the DTCs (See page ).


(c) Recheck for DTCs (See page ).


Result

Result

Proceed to

DTC is not output

A

DTC is output

B


A

USE SIMULATION METHOD TO CHECK


B

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

Test yourself

A quick Toyota 4Runner quiz: every answer comes with an explanation and a link to the manual page.