Subaru Legacy BN/BS (2015-2019) Service Manual: Dtc u0100 lost communication with ecm/pcm "a"

Subaru Legacy BN/BS (2015-2019) Service Manual / Continuously variable transmission (diagnostics) / Diagnostic procedure with diagnostic trouble code (dtc) / Dtc u0100 lost communication with ecm/pcm "a"

NOTE:

Refer to “LAN SYSTEM (DIAGNOSTICS)” for diagnostic procedure. Basic Diagnostic Procedure

1. OUTLINE OF DIAGNOSIS (ENGINE TYPE FB)

• Detect malfunction of CAN communication.

• Judge as NG when CAN communication failure occurs with the ECM.

2. EXECUTION CONDITION (ENGINE TYPE FB)

Secondary Parameters	Execution condition
12 V battery system voltage	≥ 10 V
Measured turbine shaft speed	> 0 rpm
or
Transmission range	Drive or Reverse

3. DIAGNOSTIC METHOD (ENGINE TYPE FB)

If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

Judgment Value

Malfunction Criteria	Threshold Value
CAN data from ECM	Lost

Time Needed for Diagnosis: 0.5 seconds

Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

4. OUTLINE OF DIAGNOSIS (ENGINE TYPE EZ)

• Detect malfunction of CAN communication.

• Judge as NG when CAN communication failure occurs with the ECM.

5. EXECUTION CONDITION (ENGINE TYPE EZ)

Secondary Parameters	Execution condition
12 V battery system voltage	≥ 10 V
Measured primary pulley shaft speed	> 0 rpm
or
Transmission range	Drive or Reverse

6. DIAGNOSTIC METHOD (ENGINE TYPE EZ)

If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

Judgment Value

Malfunction Criteria	Threshold Value
CAN data from ECM	Lost

Time Needed for Diagnosis: 0.5 seconds

Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

Dtc u0122 lost communication with vehicle dynamics control module

NOTE:Refer to “LAN SYSTEM (DIAGNOSTICS)” for diagnostic procedure. Basic Diagnostic Procedure1. OUTLINE OF DIAGNOSIS (ENGINE TYPE FB)• Detect malfunction of CAN communication.• ...

General description

...

Other materials:

Inspection
1. INSPECTION OF SWITCH UNIT1. Operate the switches to check the continuity between terminals.Preparation tool:Circuit testerSwitch positionTerminal No.StandardOFFA1 and A3Less than 1 -INTA1 and A3Less than 1 -LOA2 and A3Less than 1 -HIA2 and A4Less than 1 -Washer ONB2 and B3Less than 1 -2. Replace ...