DESCRIPTION
The transponder key coil is built into the transponder key amplifier and receives a key code signal from the transponder chip in the key. This signal is amplified by the amplifier, then it is output to the transponder key ECU assembly.
DTC No. |
DTC Detection Condition |
Trouble Area |
---|---|---|
B2784 |
Antenna coil is open/shorted. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
If the transponder key ECU assembly is replaced, register the key and ECU communication
ID (See page ).
PROCEDURE
1. |
READ VALUE USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Immobiliser / Data List.
(e) Read the Data List according to the display on the Techstream.
Immobiliser (Transponder Key ECU Assembly)
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
---|---|---|---|
Antenna Coil Status |
Transponder key amplifier coil condition/Normal or Fail |
Normal: Antenna coil normal Fail: Antenna coil malfunctioning |
- |
OK:
On the Techstream screen, the item displays Normal according to the chart above.
OK | ![]() |
REPLACE TRANSPONDER KEY ECU ASSEMBLY |
|
2. |
CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER) |
(a) Disconnect the transponder key ECU assembly connector.
(b) Disconnect the transponder key amplifier connector. |
|
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D22-4 (TXCT) - D21-5 (TXCT) |
Always |
Below 1 Ω |
D22-5 (AGND) - D21-7 (AGND) |
Always |
Below 1 Ω |
D22-14 (VC5) - D21-1 (VC5) |
Always |
Below 1 Ω |
D22-15 (CODE) - D21-4 (CODE) |
Always |
Below 1 Ω |
D22-4 (TXCT) - Body ground |
Always |
10 kΩ or higher |
D22-5 (AGND) - Body ground |
Always |
10 kΩ or higher |
D22-14 (VC5) - Body ground |
Always |
10 kΩ or higher |
D22-15 (CODE) - Body ground |
Always |
10 kΩ or higher |
D21-5 (TXCT) - Body ground |
Always |
10 kΩ or higher |
D21-7 (AGND) - Body ground |
Always |
10 kΩ or higher |
D21-1 (VC5) - Body ground |
Always |
10 kΩ or higher |
D21-4 (CODE) - Body ground |
Always |
10 kΩ or higher |
*1 |
Front view of wire harness connector (to Transponder Key ECU Assembly) |
*2 |
Front view of wire harness connector (to Transponder Key Amplifier) |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
3. |
INSPECT TRANSPONDER KEY AMPLIFIER (POWER SOURCE AND GROUND) |
(a) Reconnect the transponder key ECU assembly connector.
(b) Reconnect the transponder key amplifier connector. |
|
(c) Measure the voltage and resistance according to the value(s) in the table below.
Standard Voltage:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D22-14 (VC5) - Body ground |
No key is in ignition key cylinder |
Below 1 V |
D22-14 (VC5) - Body ground |
Key is in ignition key cylinder |
4.6 to 5.4 V |
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D22-5 (AGND) - Body ground |
Always |
Below 1 Ω |
*1 |
Component with harness connected (Transponder Key ECU Assembly) |
OK | ![]() |
REPLACE TRANSPONDER KEY AMPLIFIER |
NG | ![]() |
REPLACE TRANSPONDER KEY ECU ASSEMBLY |
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System Diagram
SYSTEM DIAGRAM
Input and Output Signal of Each ECU
Transmitting ECU (transmitter)
Receiving ECU
Signal
Communication Method
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