The biggest mistake people are making coming up with these off the cuff suggestions is that the key and fob programing is in the KAM memory dependent on voltage to retain it. In my experience this is not the case. The key and fob information, TMPS sensors, etc are all stored in re-writable memory (for lack of a better term) and no mater how long the battery was disconnected it would all still be there undisturbed. As a flat rate mechanic you need to quickly diagnose the issue or put your family on welfare so I tend to make large passes at diagnostics to eliminate as much as I can quickly. With my limited knowledge of the Honda my first order of business would have been to erase all keys and fobs and reprogram them. My gut says something glitched. It's not a "random" issue the OP has expressed a very specific pattern of failure. I don't want to pretend I know what the OP has done when he goes to the dealer but my experience is that when this weird stuff happens and can't be found it's due to lack of patience from the customer or the mechanics. The mechanics are not interested in losing their ass and spending hours of unpaid time looking for it and the customer needs his car or is overly concerned with the cost and is trying to micromanage the repair. This is a case where dealer management staff needs to step in and figure out how they are going to compensate the mechanic and not charge the customer out the wazoo. Not a lot of dealers are willing to do this. But then again, it's been widely propagandized on this site that Hondas are built by God himself and never have issues so we may be looking at the unicorn of all Hondas to actually have an problem.
I wanted to ask if the FOB batteries that you replaced were were brand new? My Wife's 2018 CR-V dash lit up with low battery in key FOB. I put brand brand new ones in and 3 days later it got the same alert. I bought them new. I checked with a multi meter and they were just under with 2.9 and 3 Volts. Maybe check your bat voltage. The next ones I bought were like 3.4 and 3.6. I put them in and no issues. Good luck with the issue.
Yeah, I get all that- I live it at work, too. Manufacturing puts big time demands on the techs and engineers. When you slow a line that's pushing $6-8 million/DAY out the door, people get excited fast. We are spitballing here, nothing more. No one is on the clock. The whole point of this thread is looking to get lucky with a "free" answer, no? Should we clean up and close the thread with one reply- "Take it to the dealer and let them handle it?" Second key? Valet key? Inquiring minds want to know.
Now you're just being surly. How much time should be wasted with silly black magic voodoo fixes and off the wall guesses? If someone proposes a completely ridiculous suggestion should I just keep my mouth shut and let the OP waste time and money to save someone's feelings? I think the OP would argue he is on the clock and needs the issue resolved. The reality here is from what I've read in this thread most posters do not have a clue on how the system works because most of the suggestions are comical or anecdotal. Best of intentions I'm sure but they don't help the OP fix his problem, they just waste his time chasing his tail. Unless the OP has access to the Honda scan tool I don't think there is much he can do without the dealer. It's the reality of modern cars., especially the imports. If you want to continue to frame me as a guy that that doesn't want to help that's your call. But just because you disagree with me doesn't make me wrong. Any just FYI, you have zero clue what it's like to be on flat rate regardless of your manufacturing demands. At the end of the day you get paid for your time, your family will get fed. A flat rate guy can go home with zero wages for his effort. I'm sure having a bunch of high dollar big wigs being "excited" might be unpleasant but it pales in comparison to the stress a tech has for not being able to pay his bills and feed his family because he wasted the day changing fuses and and such because the guy in charge read it was the fix on the internet somewhere.
I had seen the same issue on a '09 Civic and after changing the ignition switch fuse without resolution I moved on to the ignition switch on the column, and bam 10 minutes later and problem solved!
Sure, Dave, sure. You win. Sorry for wasting yours and everyone's time, especially Brian's. Thanks for the reminder, Dave. I needed it. Peace.
Jeez, Dave..... I thought you had the magic box that you plug in and it tells you what is wrong. The guys at Vato Zone could have fixed it by now......
The system consists of a transponder combined with a keyless transmitter, an immobilizer-keyless control unit (has built-in receiver), the driver's MICU (has built-in imoes unit), an immobilizer indicator, and the ECM/PCM. When the immobilizer key (programmed by the HDS) is inserted into the ignition switch and turned to ON, the immobilizer-keyless control unit sends power to the transponder. The transponder then sends a coded signal back to the immobilizer keyless control unit which then sends a coded signal to the ECM/PCM and the driver's (imoe unit) The ECM/PCM and driver's MICU (imoes unit) identify this coded signal, then VOLTAGE IS SUPPLIED TO THE FUEL PUMP. If the wrong key has been used or the code was not received or recognized, the indicator will FLASH once, then it will blink until the ignition switch is turned to LOCK. When the ignition switch is turned to LOCK position, the indicator will blink ten times to signal that the unit has reset correctly. then the indicator will go off. Trouble shooting procedure: Turn the ignition switch to lock > enter the vehicle, and remove the ignition key from the ignition switch, then close all the doors > operate the keyless transmitter LOCK and UNLOCK several times > IF DOOR LOCK ACTUATORS WORK NORMALLY: > Turn the ignition switch to on > back-probe and measure the voltage between immobilizer-keyless control unit 7P connector terminal No.2 and body ground > if there's battery voltage > back-probe and measure the voltage between immobilizer-keyless control unit 7P connector terminal No. 7 and body ground. IS THERE LESS THAN 0.2 V > YES - repair poor connection or an open or high resistance between immobilizer-keyless control unit 7P connector terminal No, 7 and body ground. IF THERE'S MORE THAN 0.2 V > replace the immobilizer keyless control unit. IF DOOR LOCK ACTUATORS WON'T WORK NORMALLY > check for poor ground and/or an open in the wire between immobilizer-keyless control unit 7P connector and body ground. IF THERE'S NO VOLTAGE BETWEEN IMMOBILIZER-KEYLESS CONTROL UNIT 7P CONNECTOR TERMINAL NO.2 AND BODY GROUND > check for blown No.9 (20 A) fuse in the driver's under-dash fuse/relay box. If fuse is OK, repair open in the YELLOW wire between the driver's under-dash fuse/relay box and the immobilizer-keyless control unit. IMHO.. The only shortcut when dealing with a stubborn electrical problem is go with the easy checks first (fuse, battery, etc.) after all of that checked okay then its time to get the schematic and the DVM out.
Haha sure any other time.. every so often you get lucky although random part changing isn't always recommended.