My power door locks have not worked for a long time. Since my drivers window motor needed replacement anyway, I took out the power door lock control unit and examined the pcb.

Symptoms:

When pressing the door lock switch, a click is heard. This click is actually the relays switching. To verify this, follow the procedure in the online manual:

http://www.honda.co.uk/owner/AccordM...400/16-228.pdf

I got the power door locks working on mine when following the procedure.

Repair:
Remove the control unit and and examine the pcb for any solder joints that appear to be aged. Look at the solder joint for the two white relays. Resolder the worn joints to form a well shaped joint.

Test:
Reconnect the pcb into harness and see if the door locks work.
Hopefully it should.
If not, the click must still be heard. Recheck the solder joints especially on the connector.

If It Still Fails:
I tried to contact the company of the unit to provide me with a schematic and/or parts list for the pcb, but had no reply. Most likey, a component on the pcb has failed and needs to be narrowed down. All the pcb components are easy to replace at any Radio Shack, except the two relays. These relays are hard to find. I dont think these relays can go bad because they have many switching cycles.

Last Resort:
Replace the power door lock control unit, but verify all the other components of the door lock system are working (actuators, switches, wiring, etc.)