DESCRIPTION
The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the front door outside handle assembly LH (electrical key antenna) at intervals of 0.25 seconds. For the front door outside handle assembly LH (electrical key antenna) to detect when the electrical key transmitter sub-assembly is brought close to the vehicle, a signal requesting a response from the electrical key transmitter sub-assembly is transmitted within approximately 1 m (3.28 ft.) of the driver door at intervals of 0.25 seconds. DTC B27A1 is stored by the certification ECU (smart key ECU assembly) when an open is detected between the certification ECU (smart key ECU assembly) and front door outside handle assembly LH (electrical key antenna) (between terminals CLG1 and ANT1, or terminals CG1B and ANT2).
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
Note |
---|---|---|---|---|
B27A1 |
Open in Driver Side Electrical Antenna Circuit |
An open is detected in the circuit between the certification ECU (smart key ECU assembly) and front door outside handle assembly LH (CLG1 - ANT1, CG1B - ANT2) (This is detected by the malfunction detection circuit in the certification ECU (smart key ECU assembly)) (1 trip detection logic*). |
|
|
Vehicle Condition when Malfunction Detected |
Fail-safe Operation when Malfunction Detected |
---|---|
Entry lock/unlock operation cannot be performed for driver door |
- |
DTC No. |
Data List and Active Test |
---|---|
B27A1 |
Key diagnostic mode can be used to perform troubleshooting |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Click here
Click here
PROCEDURE
1. |
CHECK CONNECTOR CONNECTION |
(a) Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and front door outside handle assembly LH.
OK:
Connectors are properly connected.
NG | ![]() |
CONNECT CONNECTORS PROPERLY |
|
2. |
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH) |
(a) Disconnect the M67 and F1 certification ECU (smart key ECU assembly) connectors.
(b) Disconnect the J3 front door outside handle assembly LH connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
M67-17 (CLG1) - J3-6 (ANT1) |
Always |
Below 1 Ω |
M67-16 (CG1B) - J3-4 (ANT2) |
Always |
Below 1 Ω |
F1-18 (E) - Body ground |
Always |
Below 1 Ω |
M67-17 (CLG1) or J3-6 (ANT1) - Body ground |
Always |
10 kΩ or higher |
M67-16 (CG1B) or J3-4 (ANT2) - Body ground |
Always |
10 kΩ or higher |
(d) Reconnect the M67 and F1 certification ECU (smart key ECU assembly) connectors.
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
3. |
CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH) |
*a |
Component with harness connected (Certification ECU (Smart Key ECU Assembly)) |
*b |
Waveform 1 |
*c |
Waveform 2 |
*d |
Waveform 3 |
*e |
Waveform 4 |
- |
- |
(a) Using an oscilloscope, check the waveform.
OK:
Tester Connection |
Condition |
Tool Setting |
Specified Condition |
---|---|---|---|
M67-17 (CLG1) - F1-18 (E) |
Procedure:
|
5 V/DIV., 500 ms/DIV. |
Pulse generation (See waveform 1) |
Procedure:
|
5 V/DIV., 100 ms/DIV. |
Pulse generation (See waveform 2) |
|
M67-16 (CG1B) - F1-18 (E) |
Procedure:
|
5 V/DIV., 500 ms/DIV. |
Pulse generation (See waveform 3) |
Procedure:
|
5 V/DIV., 100 ms/DIV. |
Pulse generation (See waveform 4) |
Click here
NG | ![]() |
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
|
4. |
REPLACE FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH |
(a) Replace the front door outside handle assembly LH with a new one or the front door outside handle assembly RH if it is functioning properly.
Click here
|
5. |
CLEAR DTC |
(a) Clear the DTCs.
Body Electrical > Smart Key > Clear DTCs
|
6. |
CHECK FOR DTC |
(a) Check for DTCs.
Body Electrical > Smart Key > Trouble CodesOK:
DTC B27A1 is not output.
OK | ![]() |
END (FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH WAS DEFECTIVE) |
NG | ![]() |
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
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CAUTION REGARDING INTERFERENCE WITH ELECTRONIC DEVICES
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therapy-pacemakers or implantable cardioverter defibrillators should maintain
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