DTC B1641: RF Unit 2 Not Connected

WARNING: This page is about a different car, the 2010 Acura TL and 2009 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.

Clear the DTCs with the HDS.
Select the MODE MENU from the HDS, then enter the SELF CHECK.
Do the SELF CHECK.
Check for DTCs with the HDS.
Is DTC B1641 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections.
Press the engine start/stop button to select the OFF mode.
Disconnect the RF unit 2 3P connector.
Disconnect keyless access control unit connector B (32P).

Check for continuity between the following RF unit 2 3P connector terminals and keyless access control unit connector B (32P) terminals.

RF UNIT 2	KEYLESS ACCESS CONTROL UNIT CONNECTOR B (32P)
No. 1	No. 18
No. 2	No. 20
No. 3	No. 31

Fig 1: Checking Continuity Between RF Unit 2 3P Connector Terminals And Keyless Access Control Unit Connector B (32P) Terminals

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 9.

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

Check for continuity between body ground and RF unit 2 3P connector terminals No. 1, No. 2, and No. 3 individually.

Fig 2: Checking Continuity Between Body Ground And RF Unit 2 3P Connector Terminals No. 1, No. 2, And No. 3
Courtesy 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 2. If the symptom goes away, replace the original RF unit 2 (see RF UNIT 2 REPLACEMENT ). If not, replace the keyless access control unit (see CONTROL UNIT INPUT TEST ).