What this code means
B1658 may mean the keyless access system is seeing a possible disconnection in the rear bumper LF antenna line.
What the vehicle may do
- Keyless access may act inconsistently near the rear of the vehicle.
- The code can also appear during a scan even when the driver complaint is limited or intermittent.
Possible fault areas
- Possible wiring or connector trouble in the rear bumper LF antenna circuit.
- Possible body control module side circuit issue.
- Possible rear bumper LF antenna issue.
Diagnostic path
What B1658 is pointing at
On this Honda CR-V Hybrid, B1658 is a keyless access fault. In plain language, the body control module may be detecting the rear bumper LF antenna line as disconnected. The driver may notice keyless access behavior that is inconsistent around the rear of the vehicle, or the code may be found during a scan with no obvious complaint. The broad fault areas are the antenna circuit, the rear bumper LF antenna connection, the body control module side of the circuit, and the antenna itself. Start with the basic troubleshooting overview so you are not jumping straight to a part.
Start with the scan tool check
Run the HDS Self Check before getting into circuit testing. If other codes are present, do not treat B1658 in isolation. Handle the multiple-code situation first using the B-CAN test-mode approach, then come back to this fault path once the network context is clear.
Check the rear antenna circuit for an open
For the EXT_TR+ and EXT_TR- open wire inspection, disconnect the rear bumper LF antenna connector, which is the 2P connector, and disconnect body control module connector C, the 66P connector. Then perform the EXT_TR+ and EXT_TR- open wire inspection. With the inspection OFF, EXT_TR+ should show less than 1 Ω, and EXT_TR- should also show less than 1 Ω. If either side is abnormal, the fault is in the circuit. Make sure the correct EXT_TR+ and EXT_TR- terminals are positively identified before probing; do not guess at terminal locations.
Check the body control module side
Move to the body control module inspection only with the external circuit known normal. For this check, disconnect the rear bumper LF antenna 2P connector. Then perform the body control module inspection. The expected result for the module internal circuit inspection is voltage. This check is tied to a permanent power supply, so do not make the decision just from whether the vehicle mode is ON or OFF, LOCK. If this inspection is abnormal, the problem is with the body control module side. This inspection can be used early because it covers the related inspection items, but if it fails, continue the individual checks so you know which item actually failed.
Last isolation point
If the circuit checks normal and the body control module inspection is normal, the remaining fault area is the rear bumper LF antenna. The takeaway is simple: B1658 is diagnosed by separating the antenna wiring from the module side, then using the remaining normal results to isolate the antenna. For more diagnostic training, visit stepdiagnostics.com.
Final check
This code is often approached by confirming the circuit path first, then separating the body control module side from the antenna side.
For more guided automotive diagnostics, visit STEP Diagnostics.
