Display Unit Buttons Do Not Work
- Turn ignition switch to ON position. Backprobing with DVOM, check for battery voltage between ground and display unit connector terminal No. 1 (White/Yellow wire) and No. 2 (White/Yellow wire), individually. See Figure . If battery voltage exists in both wires, go to next step. If battery voltage does not exist at either wire, repair open in appropriate White/Yellow wire between display unit and underhood or underdash fuse/relay box.
- Turn ignition off. Backprobing with DVOM, check for continuity between ground and display unit connector terminal No. 10 (Black wire). See Figure . If continuity exists, go to next step. If continuity does not exist, repair open or poor ground connection in Black wire between display unit and ground connector G251. See WIRING DIAGRAMS . Ground connector G251 is located at right rear of engine compartment, below Anti-Lock Brake System (ABS) modulator unit hydraulic lines.
- Disconnect navigation unit and display unit connectors. Check continuity of Black wire between display unit harness connector terminal No. 5 and navigation unit 16-pin harness connector "B" terminal No. 7. See Figure and Figure . If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between navigation unit and display unit.
- Check continuity of White wire between display unit harness connector terminal No. 15 and navigation unit 16-pin harness connector "B" terminal No. 15. See Figure and Figure . If continuity exists, go to next step. If continuity does not exist, repair open in White wire between navigation unit and display unit.
- Check for continuity between ground and display unit harness connector terminal No. 5 (Black wire) and No. 15 (White wire), and navigation unit 16-pin harness connector "B" terminal No. 7 (Black wire) and No. 15 (White wire), individually. See Figure and Figure . If continuity exists, repair short to ground in appropriate wire. See WIRING DIAGRAMS . If continuity does not exist, replace display unit.