Honda Accord: Audio Communication Line Circuit Troubleshooting

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

2. Disconnect climate control unit connector A (28P) and the audio-HVAC subdisplay (with navigation) or audio-HVAC display unit (without navigation) 12P connector.

3. Check for continuity between the following terminals of climate control unit connector A (28P) and the audio-HVAC subdisplay or display unit 12P connector.

28P:         12P:

No. 19     No. 7

No. 20     No. 8

CLIMATE CONTROL UNIT CONNECTOR A (28P)

Wire side of female terminals

AUDIO-HVAC SUBDISPLAY UNIT 12P CONNECTOR*!

AUDIO-HVAC DISPLAY UNIT 12P CONNECTOR*2

Wire side of female terminals

*1: With navigation

*2: Without navigation

Is there continuity? YES

-Go to step 4.

NO-

Repair an open in the wire between climate control unit connector A (28P) and the audio-HVAC subdisplay or display unit 12P connector.

4, Check for continuity between body ground and climate control unit connector A (28P) terminals No. 19 and No. 20 individually.

CLIMATE CONTROL UNIT CONNECTOR A (28P)

Wire side of female terminals

*1: With navigation

*2: Without navigation

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

between climate control unit connector A (28P) and the audio-HVAC control unit 12P connector.

NO

-Go to step 5.

5. Reconnect climate control unit connector A (28P).

6. Connect audio-HVAC subdisplay or display unit 12P connector terminals No. 7 and No. 8 with a jumper wire.

AUDIO-HVAC SUBDISPLAY UNIT 12P CONNECTOR* 1

AUDIO-HVAC DISPLAY UNIT 12P CONNECTOR*2

Wire side of female terminals

* 1 : With navigation

*2: Without navigation

7. Turn the ignition switch to ON (II).

8. Press and hold the DEF button and OFF button.

Is the DEF button LED blinking? YES

-Audio-HVAC subdisplay unit or display unit is faulty, replace the audio-HVAC subdisplay unit (see page 23-118) or audio-HVAC display unit (see page 23-119).

NO

-Climate control unit is faulty, replace the climate control unit (with navigation) (see page 21-190), (without navigation) (see page 21-191).