Hi guys,

Desperately trying to permanently disable factory car alarm on 2011 accord. I've replaced door switches, disconnected trunk and hood switch and alarm still sounds in the middle of the night randomly. Appears to be .common when or after it rains. Driving me crazy. Is there a way to disable it completely?

There's no information on this anywhere.
OEM alarm. Not aftermarket.

 

Was the security system something that was an accessory that was installed on your car? Or is this like randomly hitting the panic button on your key fob?

 

oem alarm system, when the issue occurs yes it is like hitting the panic button.

 

You can stop by a parts store and see if their obd scanner can read codes other than the normal obd2 codes.

You can try testing B-CAN test mode 1. You can jump the pins using a wire with double alligator clips instead of the special tool in step 4. Make sure you are jumping the correct pins on the fuse box.

Found the instructions below on a website (Honda Accord: B-CAN System Diagnosis Test Mode 1 and Test Mode 2 (without the HDS) - Multiplex Integrated Control System - Body Electrical - Honda Accord MK8 2008-2012 Service Manual) that match the directions in my oem shop manual.



Test Mode 1

Check the ECM/PCM for DTCs and troubleshoot ECM/PCM (see p a g e 11-3) or F-CAN loss o f communication errors first, then do this diagnosis if the HDS is not available.

1. Check the No. 15 (10 A) fuse in the under-hood fuse/relay box and No. 5 (7.5 A) fuse in the driver's under-dash fuse/relay box.

Are the fuses OK?
YES -Go to step 2.

NO-Find and repair the cause of the blown f u s e .

2. Remove the driver's dashboard lower cover (see page 20-166).

3. Turn the ignition switch to ON (II), and move the ceiling light switch to the middle (door) position. .

4. Connect the MPCS service connector (A) to the MICU service check connector socket (B) in the driver's under-dash fuse/relay box.


5. Wait 5 seconds, and watch the ceiling light. When the ceiling light flashes quickly once and then goes off, the system is in Test Mode 1.

6. Check for B-CAN DTCs indicated by the gauge control module odo/trip display while still in Test Mode 1.

Press the SEL/RESET button to display the next code.

After you get to the last code, the display shows END.

If no DTCs are stored, the display will read NO (see page 22-109).

NOTE: If the test times out, remove the MPCS service connector, turn the ignition switch to LOCK (0), and repeat steps 3 and 4.

Are any DTCs indicated? YES

-Go to step 7.

NO

-Go to step 10.

7. Record all DTCs and troubleshoot them in this order:

-Battery voltage DTCs

-Internal error DTCs

-Loss of communication DTCs

-Signal error DTCs

8. Clear the DTCs by pressing and holding the SEL/RESET button for at least 10 seconds.

9. You will hear a beep to confirm the codes have been cleared. Operate the devices that failed, and recheck for codes.

 

will try to make sense of this and check...thank you. no CEL light currently. when the issue is occuring i can hear an audible click constantly under the drivers dash like its coming from a relay. its normally quiet and you dont hear anything. im wondering if something is shorting out or getting wet somehow under there...

 

The directions look long, but it is really just shorting 2 pins on the fuse box.

Your car stores codes other than the CEL obd2 codes. More expensive code readers can read the other codes. The method I copied above is a way to read those codes without having to take it to the dealership.

 

checked with snapon computer. no CEL codes logged. No alarm history could be read. communication with the trunk lock could not be sensed by the snapon. will replace switch. fuses that you advised to check were ok. would the disconnected hood switch give this issue? i noticed no difference between hood switch being plugged in or unplugged...alarm still goes off...

 

Sounds like the snapon scanner indicated an issue with the trunk switch. I'm not familiar with the 08 setup. Can you use your key to open the trunk from the outside? Or do you have to release the trunk through the back seat?

Looking at the diagram, does your trunk light work properly?

 

so its 2011 model. key fob or pull latch at drivers floor are only means of opening trunk. no key hole on lid itself.

 

trunk lid light illuminates upon opening trunk.