B279A

ENGINE IMMOBILIZER: ENGINE IMMOBILIZER SYSTEM: B279A: Theft Deterrent System Communication Line High Fixation

DTC B279A - Theft Deterrent System Communication Line High Fixation

DESCRIPTION

If the communication line (EFIO-IMI) to the transponder key ECU is stuck on HI output, the ECM outputs this DTC.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CLEAR DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
NEXT -- Continue to next step.
2. CHECK FOR DTC
(a) Check for DTC Reading and Clearing Diagnostic Trouble Codes.

Result





HINT: If any DTCs other than B279A are output, troubleshoot those DTCs first.

B -- GO TO DIAGNOSTIC TROUBLE CODE CHART
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM)




(a) Disconnect the T9 ECU and E8 ECM connectors.
(b) Measure the resistance and voltage according to the value(s) in the table below.
Standard resistance:





Standard voltage





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK TRANSPONDER KEY ECU (OUTPUT)




(a) Measure the waveform.
Waveform 1 (Reference):






OK:
Waveform is output normally (see illustration).
NG -- CHECK TRANSPONDER KEY ECU (POWER SOURCE AND BODY GROUND)
OK -- REPLACE ECM
5. CHECK TRANSPONDER KEY ECU (POWER SOURCE AND BODY GROUND)




(a) Turn the ignition switch ON.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE TRANSPONDER KEY ECU