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Home >> Acura >> 2019 >> MDX Base >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Security System / Keyless Entry System - Testing & Troubleshooting (Except Hybrid) >> How to Information >> How to Troubleshoot the Keyless Access System (2016 2017 2018 2019 2020) >> Self-Diagnostic Function
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Self-Diagnostic Function

NOTE: Some models have the rear outer handle touch sensor. Perform the troubleshooting flow where applicable.

The keyless access system has a self-diagnostic function. If any malfunction and DTC are stored in the keyless access/TPMS control unit, the keyless access indicator flashes.

When malfunction is detected, the keyless access indicator flashes until the vehicle is turned to OFF (LOCK) mode.

The DTC is cleared when the battery terminal is disconnected, or by removing the No. C16 (10 A) fuse from the under-hood fuse/relay box.

DTC Keyless access indicator Description
B1601 Keyless Access Control Unit internal (CPU) error
B1602 Keyless Access Control Unit internal (EEPROM) error
B12A1 Power Control Unit Internal (CPU) Erorr
B12C5 Engine start/stop switch failure
B12C6 - Refer to: DTC Troubleshooting: B12C6 (2017 2018 2019 2020), or DTC Troubleshooting: B12C6 Electric steering lock switch C/D monitor circuit failure
B12C7 - Refer to: DTC Troubleshooting: B12C7 (2017 2018 2019 2020), or DTC Troubleshooting: B12C7(With Electric Steering Lock) (2016), or DTC Troubleshooting: B12C7 (2014 2015) Electric steering lock motor circuit failure
B1627 - Refer to: DTC Troubleshooting: B1627, or DTC Troubleshooting: B1627 (2017 2018 2019 2020) RF1 Unit disconnected (2-way transceiver or RF antenna disconnected)
B1632 MTR CONT signal error
B12D0 Power control unit IG1A circuit error
B12D1 Power control unit IG1B circuit error
B12D2 Power control unit IG2 circuit error
B12D3 Power control unit IG latch circuit error
B1640 RF1 antenna not connected or malfunction (Internal RF antenna malfunction)
B1641 - Refer to: DTC Troubleshooting: B1641 (2017 2018 2019 2020), or DTC Troubleshooting: B1641 RF2 antenna not connected or malfunction (2-way transceiver or RF antenna not connected or malfunction)
B1645 Driver's Door LF Antenna circuit short (Left-Front LF Antenna circuit short)
B1646 Driver's Door LF Antenna circuit open (Left-Front LF Antenna circuit open)
B1647 Passenger's Door LF Antenna circuit short (Right-Front LF Antenna circuit short)
B1648 Passenger's Door LF Antenna circuit open (Right-Front LF Antenna circuit open)
B1649 Driver Side Rear Passenger Door Antenna circuit short (Left-Rear LF Antenna circuit short)
B1650 Driver Side Rear Passenger Door Antenna circuit open (Left-Rear LF Antenna circuit open)
B1651 Passenger side rear passenger door antenna circuit short (Right-Rear LF Antenna circuit short)
B1652 Passenger side rear passenger door antenna circuit open (Right-Rear LF Antenna circuit open)
B1659 Front Interior LF Antenna circuit short
B1660 Front Interior LF Antenna circuit open
B1663 - Refer to: DTC Troubleshooting: B1663 (2017 2018 2019 2020), or DTC Troubleshooting: B1663 Rear Interior LF Antenna circuit short
B1664 - Refer to: DTC Troubleshooting: B1664, or DTC Troubleshooting: B1664 (2017 2018 2019 2020) Rear Interior LF Antenna circuit open
B12E0 Electric steering lock switch internal error
B12E1 - Refer to: DTC Troubleshooting: B12E1(With Electric Steering Lock) (2016), or DTC Troubleshooting: B12E1 (2017 2018 2019 2020), or DTC Troubleshooting: B12E1 (2014 2015) Electric steering lock motor internal error
B12E2 - Refer to: DTC Troubleshooting: B12E2(With Electric Steering Lock) (2016), or DTC Troubleshooting: B12E2 (2014 2015), or DTC Troubleshooting: B12E2 (2017 2018 2019 2020) Electric steering lock low level failure of MTRCUT1
DTC Keyless access indicator Description
B12E3 - Refer to: DTC Troubleshooting: B12E3, or DTC Troubleshooting: B12E3 (2017 2018 2019 2020) Electric steering lock high level failure of MTRCUT1
B12E4 - Refer to: DTC Troubleshooting: B12E4 (2014 2015), or DTC Troubleshooting: B12E4(With Electric Steering Lock) (2016) Electric steering lock high level failure of MTRCUT2
B12E5 Incorrect assembly of control unit for electric steering lock equipped vehicle
B12F0 Power control unit lost communication with electric steering lock
B12F3 Power control unit lost communication with transmission control unit
B1926 Backup Control Antenna Open or Short
B1931 Backup Control Unit No Response
NOTE: When the engine start/stop button is pressed and the mode changes to ON, the keyless access indicator comes on when any malfunction is detected.