Lexus NX: Antenna Coil Open / Short (B2784)
DESCRIPTION
When an open or short circuit is detected in the transponder key amplifier coil built into the power switch, the certification ECU (smart key ECU assembly) stores this DTC. This DTC is also stored as a past DTC.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Note |
|---|---|---|---|---|
| B2784 | Antenna Coil Open / Short | The transponder key amplifier coil built into the power switch is open (see below) or shorted (determined by communication with certification ECU (smart key ECU assembly)). (1 trip detection logic*)
|
| DTC output confirmation operation:
|
- *: Only output while a malfunction is present.
| Vehicle Condition when Malfunction Detected | Fail-safe Operation when Malfunction Detected |
|---|---|
| Hybrid control system cannot be started when transmitter battery is depleted by holding transmitter near power switch and pressing and holding power switch with shift lever in P | - |
| DTC No. | Data List and Active Test |
|---|---|
| B2784 | - |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
- When using the Techstream with the power 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 Access. 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.
-
Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
Click here
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- After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation."
PROCEDURE
| 1. | CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - POWER SWITCH) |
(a) Disconnect the I53 certification ECU (smart key ECU assembly) connector.
(b) Disconnect the I16 power switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| I53-15 (VC5) - I16-10 (VC5) | Always | Below 1 Ω |
| I53-14 (TXCT) - I16-7 (TXCT) | Always | Below 1 Ω |
| I53-13 (CODE) - I16-8 (CODE) | Always | Below 1 Ω |
| I53-12 (AGND) - I16-6 (AGND) | Always | Below 1 Ω |
| I53-15 (VC5) or I16-10 (VC5) - Body ground | Always | 10 kΩ or higher |
| I53-14 (TXCT) or I16-7 (TXCT) - Body ground | Always | 10 kΩ or higher |
| I53-13 (CODE) or I16-8 (CODE) - Body ground | Always | 10 kΩ or higher |
| I53-12 (AGND) or I16-6 (AGND) - Body ground | Always | 10 kΩ or higher |
| NG | .gif) | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
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| 2. | REPLACE POWER SWITCH |
(a) Temporarily replace the power switch with a new or known good one.
Click here
|
| 3. | CLEAR DTC |
(a) Clear the DTCs.
Body Electrical > Smart Access > Clear DTCs
|
| 4. | CHECK FOR DTC |
(a) Perform "DTC Output Confirmation Operation" procedure.
(b) Check for DTCs.
Body Electrical > Smart Access > Trouble CodesOK:
DTC B2784 is not output.
| OK | | END (POWER SWITCH WAS DEFECTIVE) |
| NG | | REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
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