On my new EM1 the remote central locking only unlocks/locks the passenger side sometimes, Infact very rarely. Similarly if I use the key in the drivers side, doesn't unlock passenger side.
Any ideas thanks

 

What year is your Civic?

Check wiring in the door wiring boots, broken leads in the drivers door is a common problem.

DO NOT just eyeball them, pull on them, door boot leads can break inside the insulation and look good but when you pull on the lead, [insulation] it will stretch at the break.

If you find broken leads, do not make the repair at the break, add lead so there is new wire where it bends.

Have you tested the switches and actuators?

Our door lock systems are "Polarity Reversing Ground At Rest" meaning both leads going to the actuators are grounds at rest, [when not locking/unlocking] when you lock or unlock the doors the ground is "lifted" from one of the leads and power, [12V+] is supplied.

If the wiring in the door boots are good, test both leads going to each actuator, all four should have full continuity to chassis ground, if they do, unplug the actuator and connect the 12V test light to the two terminals of the plug, [wire harness side] test light ground to one lead and test light probe to the other lead and rock the door lock switches for lock and unlock or use the key or remote.

If the test light does not light up in both directions, the Power Door Lock Control Unit is bad, assuming door boot wiring is good, if the test light does light up in both directions, the actuator is the problem.

You can test the actuator by supplying power and ground directly to the actuator. 94

 

Thanks for the reply! My EM1 is a 1999 I will try these things see if I can identify the problem