Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Acura TLX BaseFACTORY OEM SERVICE PROCEDURE
Keyless Access Control Unit
Keyless ACU DTCS
| DTC | Description |
|---|---|
| B1601 | Keyless access control unit (body control module) internal (CPU) error |
| B1602 | BCM (body control module) internal error (EEPROM error) |
| B1627 | RF1 unit disconnected |
| B1640 | RF1 antenna not connected or malfunction |
| B1645 | Driver's door LF antenna circuit short |
| B1646 | Driver's door LF antenna circuit open |
| B1647 | Passenger's door LF antenna circuit short |
| B1648 | Passenger's door LF antenna circuit open |
| B1649 | Driver side rear passenger door LF antenna circuit short |
| B1650 | Driver side rear passenger door LF antenna circuit open |
| B1651 | Passenger side rear passenger door LF antenna circuit short |
| B1652 | Passenger side rear passenger door LF antenna circuit open |
| B1657 | Rear bumper LF antenna circuit shorted |
| B1658 | Rear bumper LF antenna circuit open |
| B1659 | Front interior LF antenna circuit short |
| B1660 | Front interior LF antenna circuit open |
| B1663 | Rear shelf LF antenna circuit short |
| B1664 | Rear shelf LF antenna circuit open |
| U1280 | B-CAN communication bus line error (BUS-OFF) |
| U1281 | BCM (body control module) lost communication with BCM/MICU (body control module) |
| U128D | BCM (body control module) lost communication with gauge control module |
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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