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 circuit 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 Code |
DTC Detection Condition |
Trouble Area |
DTC Output Confirmation Operation |
---|---|---|---|
B27A1 |
An open circuit 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*). |
|
Any time |
Vehicle Condition when Malfunction Detected |
Fail-safe Operation when Malfunction Detected |
---|---|
Entry lock/unlock operation cannot be performed for driver door |
- |
DTC Code |
Data List and Active Test |
---|---|
B27A1 |
Key diagnostic mode can be used to perform troubleshooting |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
The smart key system (for Entry Function) 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 Entry Function) after confirming that the communication
systems are functioning properly (See page
).
PROCEDURE
1. |
CHECK CONNECTOR CONNECTION |
(a) Turn the engine switch off.
(b) 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 OUTSIDEHANDLE ASSEMBLY LH) |
(a) Disconnect the C29 certification ECU (smart key ECU assembly) connector.
(b) Disconnect the F40 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 |
---|---|---|
C29-4 (CLG1) - F40-6 (ANT1) |
Always |
Below 1 Ω |
C29-3 (CG1B) - F40-4 (ANT2) |
Always |
Below 1 Ω |
C29-11 (E) - Body ground |
Always |
Below 1 Ω |
C29-4 (CLG1) or F40-6 (ANT1) - Body ground |
Always |
10 kΩ or higher |
C29-3 (CG1B) or F40-4 (ANT2) - Body ground |
Always |
10 kΩ or higher |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
3. |
CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO DRIVER SIDEELECTRICAL KEY ANTENNA) |
(a) Connect the C29 certification ECU (smart key ECU assembly) connector.
*a |
Component with harness connected (Certification ECU (smart key ECU assembly)) |
*b |
Waveform 1 |
*c |
Waveform 2 |
*d |
Waveform 3 |
*e |
Waveform 4 |
- |
- |
(b) Connect the F40 front door outside handle assembly LH connector.
(c) Using an oscilloscope, check the waveform.
OK:
Tester Connection |
Switch Condition |
Tool Setting |
Specified Condition |
---|---|---|---|
C29-4 (CLG1) - C29-11 (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) |
|
C29-3 (CG1B) - C29-11 (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) |
NG | ![]() |
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
|
4. |
REPLACE FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH |
(a) Temporarily replace the front door outside handle assembly LH with a new
or known good one (See page
).
|
5. |
CLEAR DTC |
(a) Clear the DTCs (See page ).
|
6. |
CHECK FOR DTC |
(a) Check for DTCs (See page ).
OK:
DTC B27A1 is not output.
OK | ![]() |
END (FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH WAS DEFECTIVE) |
NG | ![]() |
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
Combination Meter ECU Communication Stop Mode
DESCRIPTION
Detection Item
Symptom
Trouble Area
Combination Meter ECU Communication Stop Mode
Either condition is met:
Communication stop for "Combination Meter" is indicated on the
"Communication Bus Ch ...
Data List / Active Test
DATA LIST / ACTIVE TEST
1. DATA LIST
HINT:
Using the Techstream to read the Data List allows the values or states of switches,
sensors, actuators and other items to be read without removing any parts. This non-intrusive
inspection can be very useful because intermittent conditions or signals ...
Disassembly
DISASSEMBLY
PROCEDURE
1. REMOVE TELEPHONE MICROPHONE ASSEMBLY
Click here
2. REMOVE MICROPHONE CASE
HINT:
Use the same procedure for Double Cab.
Click here
3. REMOVE NO. 1 ROOF WIRE (w/ Vanity Light)
(a) w/ EC Mirror:
(1) Remove the No. 1 roof wire.
...