DESCRIPTION The
certification ECU (smart key ECU assembly) generates a request signal
and transmits the signal to the No. 1 indoor electrical key antenna
assembly (front floor). For the No. 1 indoor electrical key antenna
assembly (front floor) to detect when the electrical key transmitter
sub-assembly is in the cabin, the signal from the certification ECU
(smart key ECU assembly) requesting a response from the electrical key
transmitter sub-assembly is transmitted inside the vehicle. DTC B27A5 is
stored by the certification ECU (smart key ECU assembly) when an open
is detected between the certification ECU (smart key ECU assembly) and
No. 1 indoor electrical key antenna assembly (front floor) (between
terminals CLG5 and ANTE5, or terminals CG5B and CLGB). |
DTC No. | Detection Item |
DTC Detection Condition | Trouble Area |
Note | | B27A5 |
Open in Front Floor Electrical Key Oscillator Circuit |
An
open is detected in the circuit between the certification ECU (smart
key ECU assembly) and No. 1 indoor electrical key antenna assembly
(front floor) (CLG5 - ANTE5, CG5B - CLGB) (1 trip detection logic*). |
- Certification ECU (smart key ECU assembly)
- No. 1 indoor electrical key antenna assembly (front floor)
- Wire harness or connector
|
|
- *: Only output while a malfunction is present.
Vehicle Condition and Fail-safe Operation when Malfunction Detected |
Vehicle Condition when Malfunction Detected |
Fail-safe Operation when Malfunction Detected | |
When electrical key transmitter sub-assembly is in front seat area:
- Power source mode does not change when engine switch pressed
- Electrical key transmitter sub-assembly locked inside vehicle
| - | Related Data List and Active Test |
DTC No. | Data List and Active Test | |
B27A5 | Key diagnostic mode can be used to perform troubleshooting | WIRING DIAGRAM
 CAUTION / NOTICE / HINT
NOTICE:
- When using the Techstream with the engine switch off, connect the
Techstream to the DLC3 and turn a courtesy light switch on and off at
intervals of 1.5 seconds or less until communication between the
Techstream and the vehicle begins. Then select the vehicle type under
manual mode and enter the following menus: Body Electrical / Smart Key.
While using the Techstream, periodically turn a courtesy light switch on
and off at intervals of 1.5 seconds or less to maintain communication
between the Techstream and the vehicle.
- The smart key system (for Start Function, Gasoline Model) uses the LIN
communication system and CAN communication system. Inspect the
communication function by following How to Proceed with Troubleshooting.
Troubleshoot the smart key system (for Start Function, Gasoline Model)
after confirming that the communication systems are functioning
properly.
Click here 
- Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
Click here
- After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".
PROCEDURE |
1. | CHECK NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR) |
(a)
Check that the connectors are properly connected to the certification
ECU (smart key ECU assembly) and No. 1 indoor electrical key antenna
assembly (front floor). OK: Connectors are properly connected.
| NG |
 | CONNECT CONNECTORS PROPERLY |
|
OK |
 | |
| 2. |
CHECK
HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO.
1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR)) |
(a) Disconnect the G40 certification ECU (smart key ECU assembly) connector.
(b) Disconnect the G42 No. 1 indoor electrical key antenna assembly (front floor) connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance: |
Tester Connection | Condition |
Specified Condition | |
G40-8 (CLG5) - G42-1 (ANTE5) |
Always | Below 1 Ω | |
G40-9 (CG5B) - G42-3 (CLGB) |
Always | Below 1 Ω |
(d) Reconnect the G40 certification ECU (smart key ECU assembly) connector.
| NG |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
OK | |
| |
| 3. |
CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR)) |
|
*a | Component with harness connected
(Certification ECU (Smart Key ECU Assembly)) |
*b | Waveform | |
*c | For 30 seconds after any door closed |
*d | After 30 seconds or more have elapsed since any door closed |
(a) Using an oscilloscope, check the waveform. OK: |
Tester Connection | Condition |
Tool Setting | Specified Condition | |
G40-8 (CLG5) - G40-18 (E) | Procedure:
- Engine switch off
- Electrical key transmitter sub-assembly not inside vehicle
- Within 30 seconds of closing any door
| 2 V/DIV., 500 ms/DIV. |
Pulse generation (See waveform) | |
G40-9 (CG5B) - G40-18 (E) | Procedure:
- Engine switch off
- Electrical key transmitter sub-assembly not inside vehicle
- Within 30 seconds of closing any door
| 2 V/DIV., 500 ms/DIV. |
Pulse generation (See waveform) |
| OK |
| REPLACE NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR) |
| NG |
| REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) | |
