DTC B27A7: Open in Inside Luggage Compartment Electrical Key Oscillator Circuit [11/2015 - ]: Procedure

CHECK CONNECTOR CONNECTION

Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and No. 3 indoor electrical key antenna assembly (inside luggage compartment).

Connectors are properly connected.

Result

Proceed to
OK
NG

Result:

CONNECT CONNECTORS PROPERLY

Result:

See step 2

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT))

Disconnect the M59 and F1 certification ECU (smart key ECU assembly) connectors.
Disconnect the M31 No. 3 indoor electrical key antenna assembly (inside luggage compartment) connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
M59-11 (CLG7) - M31-1 (ANTE7)	Always	Below 1 Ω
M59-10 (CG7B) - M31-3 (CLGB)	Always	Below 1 Ω
F1-18 (E) - Body ground	Always	Below 1 Ω
M59-11 (CLG7) or M31-1 (ANTE7) - Body ground	Always	10 kΩ or higher
M59-10 (CG7B) or M31-3 (CLGB) - Body ground	Always	10 kΩ or higher

Reconnect the M59 and F1 certification ECU (smart key ECU assembly) connectors.

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR

Result:

See step 3

CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT))

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Component with harness connected (Certification ECU (Smart Key ECU Assembly))	*b	Waveform 1
*c	For 30 seconds after any door closed	*d	After 30 seconds or more have elapsed since any door closed

Using an oscilloscope, check the waveform.

Tester Connection	Condition	Tool Setting	Specified Condition
M59-11 (CLG7) - F1-18 (E)	Procedure: Power 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 1)
M59-10 (CG7B) - F1-18 (E)	Procedure: Power 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 1)

Result

Proceed to
OK
NG

Result:

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL [11/2015 - 12/2018] , or refer to REMOVAL [12/2018 - 07/2020] , or refer to REMOVAL [07/2020 - ]

Result:

See step 4

REPLACE NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT)

Temporarily replace the No. 3 indoor electrical key antenna assembly (inside luggage compartment) with a new or known good one.

HINT:

Refer to REMOVAL [11/2015 - 12/2018] , or refer to REMOVAL [12/2018 - ]

Result

Proceed to
NEXT

Result:

See step 5

CLEAR DTC

Clear the DTCs.

Body Electrical > Smart Key > Clear DTCs

Result

Proceed to
NEXT

Result:

See step 6

CHECK FOR DTC

Check for DTCs.

Body Electrical > Smart Key > Trouble Codes

Result

Result	Proceed to
B27A7 is not output	A
B27A7 is output	B

Result:

END (NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT) WAS DEFECTIVE)

Result:

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL [11/2015 - 12/2018] , or refer to REMOVAL [12/2018 - 07/2020] , or refer to REMOVAL [07/2020 - ]