DESCRIPTION
If the communication line (EFIO-IMI) to the transponder key ECU is stuck on HI output, the ECM stores this DTC.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B279A | The communication line (EFIO-IMI) between the ECM and transponder key ECU is stuck on HI output for 6 seconds or more. |
|
WIRING DIAGRAM
INSPECTION PROCEDURE
Tech Tips
When the transponder key ECU and/or ECM is replaced, reregister the ECU - ECM communication ID.
PROCEDURE
CLEAR DTC
Clear the DTC Click here.
| NEXT |
|
CHECK FOR DTC
Check for DTC Click here.
| Result | Proceed to |
|---|---|
| DTC B279A is output | A |
| DTC B279A and other DTCs are output | B |
Tech Tips
If any DTCs other than B279A are output, troubleshoot those DTCs first.
| B |
|
GO TO DIAGNOSTIC TROUBLE CODE CHART Click here |
| A |
|
CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM)
| *1 | Front view of wire harness connector (to Transponder Key ECU) |
| *2 | Front view of wire harness connector (to ECM) |
Disconnect the D102 ECU connector.
Disconnect the A40 ECM connector.
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 |
|
CHECK TRANSPONDER KEY ECU (OUTPUT)
Measure the waveform.
| Terminal No. (Symbol) | Tool Setting | Switch Condition |
|---|---|---|
| D102-13 (EFIO) - D102-16 (GND) | 10 V/DIV., 500 msec./DIV. | Ignition switch ON |
| OK |
|---|
| Waveform is output normally (see illustration). |
Tech Tips
Replace the ECM (for 1ZR-FAE) Click here.
Replace the ECM (for 2ZR-FAE) Click here.
Replace the ECM (for 3ZR-FAE) Click here.
Replace the ECM (for 3ZR-FE) Click here.
| NG |
|
CHECK TRANSPONDER KEY ECU (POWER SOURCE AND BODY GROUND) Click here |
| OK |
|
REPLACE ECM
CHECK TRANSPONDER KEY ECU (POWER SOURCE AND BODY GROUND)
| *1 | Component with harness connected (Transponder Key ECU) |
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