DTC B1931: Remote Slot Control Unit no Response

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.

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 ).

Clear the DTCs with the HDS.
Turn the keyless access system mode switch OFF.
Insert the remote into the remote slot.
Do the procedure 10 times: Press the engine start/stop button to select the OFF, ACC, ON, and OFF mode.
Select the ONE-PUSH START from the system select menu with the HDS.
Select the SLOT UNIT and check for DTCs with the HDS.
Is DTC B1931 indicated?

YES -Go to step 7.

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.
Check for loose connections in the remote slot 16P connector.
Is the connections OK?

YES -Go to step 9.

NO -Replace the faulty connections, and then recheck the system.
Measure the voltage between body ground and the remote slot 16P connector terminal No. 1.

Fig 1: Measuring Voltage Between Body Ground And The Remote Slot 16P Connector Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage OK?

YES -Go to step 10.

NO -Check for blown No. 12 (10 A) fuse in the passenger's under-dash fuse/relay box and an open or a short to ground in the wire. If the fuse and wire are OK, replace the remote slot (See REMOTE SLOT TEST/REPLACEMENT ).
Disconnect the remote slot 16P connector.
Check for continuity between body ground and remote slot 16P connector terminals No. 7 and No. 15 individually.

Fig 2: Checking Continuity Between Body Ground And Remote Slot 16P connector terminals No. 7 and No. 15
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 12.

NO -Repair an open or high resistance in the wire or poor ground (G403).
Reconnect the remote slot 16P connector.
Press the engine start/stop button to select the ON mode.
Measure the voltage between body ground and remote slot 16P connector terminal No. 11.

Fig 3: Measuring Voltage Between Body Ground And Remote Slot 16P Connector Terminal No. 11
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage OK?

YES -Go to step 18.

NO -Go to step 15.
Press the engine start/stop button to select the OFF mode.
Disconnect the remote slot control unit 40P connector.
Check for continuity between body ground and remote slot 16P connector terminal No. 11.

Fig 4: Checking For Continuity Between Body Ground And Remote Slot 16P Connector Terminal No. 11
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Substitute a known-good remote slot. If the symptom goes away, replace the original remote slot (See REMOTE SLOT TEST/REPLACEMENT ). If not, replace the remote slot control unit (see REMOTE SLOT CONTROL UNIT ).
Press the engine start/stop button to select the OFF mode.
Disconnect the remote slot control unit 40P connector.
Disconnect the remote slot 16P connector.
Check for continuity between body ground and remote slot 16P connector terminals No. 2 and No. 9 individually.

Fig 5: Checking Continuity Between Body Ground And Remote Slot 16P Connector Terminals No. 2 And No. 9
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Go to step 22.
Check for continuity between remote slot control unit 40P connector terminals No. 9, No. 29, and No. 28, and remote slot 16P connector terminals No. 2, No. 9, and No. 11 respectively.

Fig 6: Checking Continuity Between Remote Slot Control Unit 40P Connector Terminals And Remote Slot 16P Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Substitute a known-good remote slot. If the symptom goes away, replace the original remote slot (See REMOTE SLOT TEST/REPLACEMENT ). If not, replace the remote slot control unit (see REMOTE SLOT CONTROL UNIT ).

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