B1627

DTC Troubleshooting: B1627, B1640

DTC B1627: RF Unit 1 Not Connected

DTC B1640: RF Unit 1 Circuit Malfunction

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II).

3. Select the MODE MENU from the HDS, then enter the SELF CHECK.

4. Do the SELF CHECK.

5. Check for DTCs with the HDS.

Is DTC B1627 and/or B1640 indicated?
YES - Go to step 6.

NO - Go to step 12.


6. Turn the ignition switch to LOCK (0).

7. Disconnect the RF unit 1 6P connector.

8. Disconnect keyless access control unit connector C (17P).

9. Check for continuity between the following RF unit 1 6P connector terminals and keyless access control unit connector C (17P) terminals.





Is there continuity?
YES - Go to step 10.

NO - Repair open in the wire.










10. Check for continuity between body ground and RF unit 1 6P connector terminals No. 1, No. 2, No. 3, No. 4, No. 5, and No. 6 individually.

Is there continuity?
YES - Repair short to ground in the wire.

NO - Go to step 11.






11. Reconnect the RF unit 1 6P connector and keyless access control unit connector C (17P).

12. Connect the voltmeter between RF unit 1 6P connector terminal No. 5 and body ground.






13. Select the FUNCTION TEST from the HDS, and do the RF1 RXVCC DRIVING.

Does the voltage change from 0 to about 5 V?
YES - Go to step 14.

NO - Replace the keyless access control unit.


14. Connect the voltmeter between RF unit 1 6P connector terminal No. 6 and body ground.






15. Select the FUNCTION TEST from the HDS, and do the RF1 TXVCC DRIVING.

Does the voltage change from 0 to about 5 V?
YES - Go to step 16.

NO - Replace the keyless access control unit.


16. Connect the voltmeter between RF unit 1 6P connector terminal No. 3 and body ground.






17. Select the FUNCTION TEST from the HDS, and do the RF1 TXDDC OUTPUT.

Does the voltage change from 0 to about 5 V?
YES - Replace the RF unit 1.

NO - Replace the keyless access control unit.