2002 civic ex - all at once: keyless entry stopped working, opened door with key, got inside the car and the master power lock did not work; dome light did not work with door open; door chime did not work with car running and door open; and parking brake light stayed when car was running and when brake was not engaged, A/C not working. It all happened at once. I had locked the car just a few minutes earlier with the keyless entry. Checked brake fluid, it was ok. Checked for blown fuses there were none.

I replaced my original MCU with a used MCU, problem continues.

Appreciate any help.

 

There is a way to retrieve trouble codes and diagnose problems with the Multiplex Control Unit, but it requires a special tool (ref no. 1 in diagram 1) that plugs into the Multiplex Control Inspection Connector (circled in red in diagram 2). See chapter 22 of the 02-03 service manual at link in my signature for more details. I presume that this special tool can be purchased from Honda. It's also possible that a jumper wire can serve as an alternative, though I'm not absolutely sure about this.

 

Thanks RonJ for the links.
Previously I went to the Dealer andnone DTC were detected, they suggestchange MCU for $300 and continue testing ...

 

In this case, the next step would be to perform the mode 2 test and the MCU input tests described in the 02-03 service manual.

 

Hey Ron (not to thread jack....much). Those manuals that you have links to are great! Do you know of any other sites for other manufacturers? Specifically, 2002 Ford Ranger and 1972 Corvette?

I've googled all night and couldn't find any.

(Okay. Back to our regularly scheduled programming)

 

Sorry can't help you with those manuals. Searching Ford and Chevy forums would be your best bet.