Toyota Tacoma manuals

Toyota Tacoma (2015-2018) Service Manual: Lost Communication with ECM / PCM "A" (U0100,U0122)

Toyota Tacoma (2015-2018) Service Manual / Vf2cm Transfer / Touch Select 2-4 And High-low System / Lost Communication with ECM / PCM "A" (U0100,U0122)

DESCRIPTION

This DTC is output when communication is lost with the skid control ECU (brake actuator assembly) or ECM.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

U0100

Lost Communication with ECM / PCM "A"

  • Diagnosis Condition: Ignition switch turned to ON (3 seconds elapse after ignition switch is turned to ON)
  • Malfunction Status: Communication is lost between ECM and 4 wheel drive control ECU
  • Malfunction Time: 1.85 seconds or more
  • Other: 1 trip detection logic

CAN communication system

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

NOTICE:

  • When the data in the ECM and skid control ECU (brake actuator assembly) is being overwritten, a message is displayed on the multi-information display and the 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.
  • Clear all DTCs, since DTCs are stored after the data in the ECM or 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

A

CHECK CAN COMMUNICATION SYSTEM

B

USE SIMULATION METHOD TO CHECK

Clutch Switch Circuit
DESCRIPTION While depressing the clutch pedal, the clutch start switch assembly sends a signal to terminal MTN of the 4 wheel drive control ECU. While the signal is input, switching between H4 an ...

4WD Control Switch Circuit
WIRING DIAGRAM PROCEDURE 1. CONFIRM PROBLEM SYMPTOM (a) Confirm the problem symptoms. Result Result Proceed to The 4WD ind ...

Other materials:

Definition Of Terms
DEFINITION OF TERMS Term Definition Monitor description Description of what the ECM monitors and how it detects malfunctions (monitoring purpose and details). Related DTCs Group of diagnostic trouble codes that are ou ...

Terminals Of Ecu
TERMINALS OF ECU 1. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (a) Disconnect the 1D and 1F driver side junction block connectors. (b) Measure the voltage and resistance according to the value(s) in the table below. HINT: Measure the values on the wire harness side with the connectors ...

If your vehicle needs to be towed
If towing is necessary, we recommend having your vehicle towed by your Toyota dealer or a commercial towing service, using a lift-type truck or a flat bed truck. Use a safety chain system for all towing, and abide by all state/provincial and local laws. The wheels and axle on the ground must b ...

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