DESCRIPTION
When the communication line (IMI - EFIO) between the ECM and certification ECU (smart key ECU assembly) is stuck high, the ECM stores this DTC.
DTC Code |
DTC Detection Condition |
Trouble Area |
DTC Output Confirmation Operation |
---|---|---|---|
B279A12 |
The communication line (IMI - EFIO) between the ECM and certification ECU (smart key ECU assembly) is stuck high (1 trip detection logic*1). |
|
Turn the engine switch on (IG) and wait 6 seconds. |
Vehicle Condition when Malfunction Detected |
Fail-safe Operation when Malfunction Detected |
---|---|
Engine cannot be started (initial ignition occurs and engine cranks, then ignition stops) |
Engine cannot be started |
DTC Code |
Data List and Active Test |
---|---|
B279A12 |
- |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
HINT:
When DTC B279A12 and the certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.
PROCEDURE
1. |
CLEAR DTC |
(a) Clear the DTCs (See page ).
|
2. |
CHECK FOR DTC |
(a) Turn the engine switch on (IG) and wait 10 seconds.
(b) Check for DTCs (See page ).
Result |
Proceed to |
---|---|
DTC or B279A12 is output |
A |
DTC or B279A12 and other DTCs are output |
B |
HINT:
If DTCs other than DTC B279A12 are output, troubleshoot those DTCs first.
B | ![]() |
GO TO DIAGNOSTIC TROUBLE CODE CHART |
|
3. |
CHECK CONNECTION OF CONNECTOR |
(a) Turn the engine switch off.
(b) Check that the connectors are properly connected to the ECM and certification ECU (smart key ECU assembly).
OK:
Connectors are properly connected.
NG | ![]() |
CONNECT CONNECTORS PROPERLY |
|
4. |
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ECM) |
(a) Disconnect the C27 certification ECU (smart key ECU assembly) connector.
(b) Disconnect the E14 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
C27-6 (EFIO) - E14-8 (IMI) |
Always |
Below 1 Ω |
C27-6 (EFIO) or E14-8 (IMI) - Body ground |
Always |
10 kΩ or higher |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
5. |
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
(a) Replace the certification ECU (smart key ECU assembly) with a new one (See
page ).
|
6. |
REGISTER RECOGNITION CODES |
(a) Register the key (See page ).
|
7. |
REGISTER ECU COMMUNICATION ID |
(a) Register the ECU communication ID (See page
).
|
8. |
CLEAR DTC |
(a) Clear the DTCs (See page ).
|
9. |
CHECK FOR DTC |
(a) Check for DTCs (See page ).
HINT:
Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.
OK:
DTC B279A12 is not output.
OK | ![]() |
END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE) |
NG | ![]() |
REPLACE ECM |
Removal
REMOVAL
CAUTION / NOTICE / HINT
NOTICE:
When replacing the windshield glass of a vehicle equipped with a forward recognition
camera, make sure to use a Toyota genuine part. If a non-Toyota genuine part is
used, the forward recognition camera may not be able to be installed due to a missing
...
Inverter Relay
On-vehicle Inspection
ON-VEHICLE INSPECTION
PROCEDURE
1. INSPECT INVERTER RELAY
(a) Check the resistance.
(1) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
...
Installation
INSTALLATION
PROCEDURE
1. INSTALL HAZARD WARNING SIGNAL SWITCH ASSEMBLY (AIR CONDITIONING CONTROL ASSEMBLY)
(for Automatic Air Conditioning System)
(a) Connect the connectors.
(b) Engage the 8 clips to hazard warning signal switch assembly (air conditioning
control assembly).
2. INSTALL HAZ ...