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Engine Immobiliser (Diagnostic Codes & Circuit Tests): Overview Lexus RX III

Door Locks & Anti-Theft Systems 6 illustrations ~543 words

DESCRIPTION

This DTC is stored when the ID for the remote engine starter is not registered or the certification ECU (smart key ECU assembly) does not respond, even though the remote engine starter system (Toyota supplied part) has been operated to start the engine

DTC No.DTC Detection ConditionTrouble Area
B2779Remote engine starter communication error, response not possible or ID not registered.Wire harness or connector Remote engine starter wire harness Remote engine starter ECU assembly Main body ECU (Multiplex network body ECU) Certification ECU (smart key ECU assembly)

Scheme 310

Scheme 310: WIRING DIAGRAM

This DTC is stored when the ID for the remote engine starter is not registered or the certification ECU (smart key ECU assembly) does not respond, even though the remote engine starter system (Toyota supplied part) has been operated to start the engine

DTC No.DTC Detection ConditionTrouble Area
B2779Remote engine starter communication error, response not possible or ID not registered.Wire harness or connector Remote engine starter wire harness Remote engine starter ECU assembly Main body ECU (Multiplex network body ECU) Certification ECU (smart key ECU assembly)

This DTC is stored when there is an open or short in the transponder key coil (built into the engine switch).

DTC No.DTC Detection ConditionTrouble Area
B2784Transponder key coil is open or shorted.Wire harness or connector Engine switch Certification ECU (Smart key ECU assembly)

Scheme 311

Scheme 311: WIRING DIAGRAM

This DTC is stored when there is an open or short in the transponder key coil (built into the engine switch).

DTC No.DTC Detection ConditionTrouble Area
B2784Transponder key coil is open or shorted.Wire harness or connector Engine switch Certification ECU (Smart key ECU assembly)

This DTC is stored when the engine switch power source supply line is open or shorted.

DTC No.DTC Detection ConditionTrouble Area
B278AEngine switch power source supply line is open or shorted.Wire harness or connector Engine switch Certification ECU (Smart key ECU assembly)

Scheme 312

Scheme 312: WIRING DIAGRAM

This DTC is stored when the engine switch power source supply line is open or shorted.

DTC No.DTC Detection ConditionTrouble Area
B278AEngine switch power source supply line is open or shorted.Wire harness or connector Engine switch Certification ECU (Smart key ECU assembly)

This DTC is output when the ID code box (immobilizer code ECU) detects an internal malfunction.

DTC No.DTC Detection ConditionTrouble Area
B2790ID code box (Immobilizer code ECU) detects internal malfunctionID code box (Immobilizer code ECU) Certification ECU (Smart key ECU assembly)

This DTC is output when the ID code box (immobilizer code ECU) detects an internal malfunction.

DTC No.DTC Detection ConditionTrouble Area
B2790ID code box (Immobilizer code ECU) detects internal malfunctionID code box (Immobilizer code ECU) Certification ECU (Smart key ECU assembly)

This DTC is stored when one of the following occurs: 1) the ECM detects an error in its own communication with the ID code box (immobilizer code ECU); 2) the ECM detects an error in the communication lines; or 3) the ECU communication ID between the ID code box (immobilizer code ECU) and ECM is different and an engine start is attempted.

HINT

Before troubleshooting this DTC, make sure that no certification ECU (smart key ECU assembly) DTCs are present. If present, troubleshoot the certification ECU (smart key ECU assembly) DTCs first.

DTC No.DTC Detection ConditionTrouble Area
B2799One of the following conditions is met: Error in communication between ECM and ID code box (immobilizer code ECU) Error in communication lines Communication ID is different between ID code box (immobilizer code ECU) and ECM during communicationWire harness or connector ECM ID code box (immobilizer code ECU)

Scheme 313

Scheme 313: WIRING DIAGRAM

This DTC is stored when one of the following occurs: 1) the ECM detects an error in its own communication with the ID code box (immobilizer code ECU); 2) the ECM detects an error in the communication lines; or 3) the ECU communication ID between the ID code box (immobilizer code ECU) and ECM is different and an engine start is attempted.

HINT

Before troubleshooting this DTC, make sure that no certification ECU (smart key ECU assembly) DTCs are present. If present, troubleshoot the certification ECU (smart key ECU assembly) DTCs first.

DTC No.DTC Detection ConditionTrouble Area
B2799One of the following conditions is met: Error in communication between ECM and ID code box (immobilizer code ECU) Error in communication lines Communication ID is different between ID code box (immobilizer code ECU) and ECM during communicationWire harness or connector ECM ID code box (immobilizer code ECU)

If the communication line (EFIO - IMI) to the ID code box (immobilizer code ECU) is stuck high output (e. g. shorted to +B), the ECM stores this DTC.

DTC No.DTC Detection ConditionTrouble Area
B279AWhen the communication line (EFIO - IMI) between ECM and ID code box (immobilizer code ECU) is stuck high output.Wire harness or connector ID code box (immobilizer code ECU) ECM

Scheme 314

Scheme 314: WIRING DIAGRAM

If the communication line (EFIO - IMI) to the ID code box (immobilizer code ECU) is stuck high output (e. g. shorted to +B), the ECM stores this DTC.

DTC No.DTC Detection ConditionTrouble Area
B279AWhen the communication line (EFIO - IMI) between ECM and ID code box (immobilizer code ECU) is stuck high output.Wire harness or connector ID code box (immobilizer code ECU) ECM

If an ECM that is incompatible with the engine immobilizer system is installed, the ECM stores this DTC.

DTC No.DTC Detection ConditionTrouble Area
B279CWhen an ECM that is incompatible with engine immobilizer system is installed.ECM

If an ECM that is incompatible with the engine immobilizer system is installed, the ECM stores this DTC.

DTC No.DTC Detection ConditionTrouble Area
B279CWhen an ECM that is incompatible with engine immobilizer system is installed.ECM

The security indicator light blinks continuously due to a continuous signal received from the certification ECU (smart key ECU assembly) while the engine immobilizer is set.

Scheme 315

Scheme 315: WIRING DIAGRAM

The security indicator light blinks continuously due to a continuous signal received from the certification ECU (smart key ECU assembly) while the engine immobilizer is set.