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DTC B1640: RF Unit Not Connected

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B- CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B- CAN SYSTEM DIAGNOSIS TEST MODE A ).
  1. Clear the DTCs with the HDS.
  2. Select the MODE MENU from the HDS, then enter the SELF CHECK.
  3. Do the SELF CHECK.
  4. Check for DTCs with the HDS.

    Is DTC B1640 indicated? 

    YES  - Go to step 5.

    NO  - Intermittent failure, the system is OK at this time. Check for loose or poor connections.

  5. Press the engine start/stop button to select the OFF mode.
  6. Disconnect the RF unit 3P connector.
  7. Disconnect keyless access control unit connector B (32P).
  8. Check for continuity between the following RF unit 3P connector terminals and keyless access control unit connector B (32P) terminals.
    Fig 1: Checking Continuity Between Following RF Unit 3P Connector Terminals And Keyless Access Control Unit Connector B (32P) Terminals
    G08067678Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 9.

    NO  - Repair an open or high resistance in the wire.

  9. Check for continuity between body ground and RF unit 3P connector terminals No. 1, No. 2, and No. 3 individually.
    Fig 2: Checking Continuity Between Body Ground And RF Unit 3P Connector Terminals No. 1, No. 2, And No. 3 Individually
    G08067679Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair a short to ground in the wire.

    NO  - Substitute a known- good RF unit. If the symptom goes away, replace the original RF unit (see RF UNIT REPLACEMENT  ). If not, replace the keyless access control unit (see KEYLESS ACCESS CONTROL UNIT  ).