Discharged Battery & AECS issues

[nvrquit]

Here's one for the class to ponder.....

 

Used our 96 OBW to ferry the wife to work and return home today. No problems starting, at any lights or stop signs(in other words, stopping and starting). Pulled back into garage and shut down was normal. Go to leave to pick-up wife later the same day(not unusual) and nothing at first, no dash lights, no radio(it was left on previously), no starter solenoid clicking... nada. Turn key back to Off position and then to ACC, nothing. Turn key to On, dash lights at first, then dim to nothing. No output from radio the entire time. Return key to Off position and now a constant ticking at a constant interval from under the dash area.

 

Pop the hood and pull Main Fuse/Relay Box cover and began pulling the 45A main fuses starting with SBF #3(no change to sound), then SBF #4...Bingo, ticking sound stops. Hmmm......

 

Checked the battery and uh-oh, the plates are exposed and a static voltage reading is 12.74 VDC. Cleaned battery posts & cable clamps, then re-attached. Topped off all cells with distilled water(taking nearly a full quart to accomplish, not good at all) and rechecked static VDC with DMM; +12.51 VDC. Ooohhh, this is not good. Re-install SBF #4, and not only does clicking re-occur, but now the corner lamps flash as if the emergency flashers are activated... and they weren't. Hmmmm, remove interior fuse box cover and then ignition switch fuse... no effect on clicking from under dash area and corner lamps continue to flash. Track down ticking sound to Automotive Electronic Control System unit(JA64000 DX9 on label). Oh yeah, the ATM interlock in Park will not disengage either(gotta be the AECS).

 

Waited approximately one hour and re-examined. Now the dash lights, but AECS still ticking and corner lights still flash when SBF #4 is installed(which it must be for system operation). Though, now the radio will play and dash lights are back. It's too bad I don't have factory or even Haynes manual for the current OBW's we own(96 & 99), as diagnosis would be a bit easier with some system info.

 

It's too bad the battery charger was somehow lost when we moved last year, as I'd slow charge the battery and spec-grav the cells, to see if the battery is shot(most likely is) and I'm also wondering if the AECS might have been affected by a varying voltage level(I've seen EEPROM's scrambled in a similar manner). I'll try a battery swap-out with the 99 OBW and see what that effects.

 

Anyone got a suggestion that's worthwhile? Thanks for any feedback!

[ShawnW]

Take the battery out and to a parts store. Have it tested. If bad, Replace and start there. Maybe you cleaned the interior and switched the park light switch on?

[friendly_jacek]

is AECS the same thing as ECU?

 

I have never heard of discharged battery frying electronics. But I guess it could happen.

On the other hand, I had a tach fried on my boat when a battery cable was loose and sparked.

 

Was this your original battery since 1996?

[1 Lucky Texan]

The security system can also freak out. Be prepared to use the fob to lock/unlock a cycle or two. The system may think the car's being stolen!

 

 

Carl

[nvrquit]

Battery rebounded overnight and static VDC reading with the DMM is now 12.71 +VDC. Flashing corner lamps and dash illumination lights were still occurring and a puzzle. Ignition system now worked and ATM is operable (Park interlock no longer an issue) and vehicle would start, run without hesitation at idle (in garage) and no dash warning (read that as idiot) lights displayed (though the Airbag light was displayed for a longer time than ever previously encountered, but it did go out). Hmmmm....

 

 

 

Battery is the original, with some corrosion present around positive terminal & clamp so, I disconnected and cleaned both + & - clamps, terminals and battery top with the standard baking soda/water mix and then a good fresh water rinse. Dried all components, cleaned clamp & teminals (posts) with a standard post/clamp tool and reconnected appropriately.

 

 

 

Now here's why I know I should have a factory or Haynes manual. Directly in front of the battery, there's yellow decal/label on the front cross member. Guess what the text indicates regarding battery being disconnected (besides the usual radio/ECS reset deal)? The remote entry system upon reconnecting of the battery will flash the corner lamps as if the system was in "panic mode"(not all remote entry systems have such a mode) and how to reset the system to alleviate this condition ! Can anyone give me a "Duh"? Halleluiah!

 

 

 

Following the nice instructions on the pretty little decal/label and a 20 minute road test later, things seem to be back to normal. Of course the battery will still require a spec-grav test of all cells and perhaps a night on the charger (slow rate). Replacement of said battery may be needed (well, it is the original battery after all).

 

 

 

 

 

BTW ShawnW, all switches were checked for operational non-involvement (in other words, to make sure any/all were not the cause of any unrelated but possible confusion factor). In my past life (actually still current life, just a different stage ), I wrenched a bit before getting into the parts end of the trade. Then I got the brainy idea of going back to school... electronics.

 

Friendly jacek: not necessarily "frying" any component, but a partial scramming or such of an EEPROM has been known to occur(though rare these days) on a varying high>low>high voltage fluctuation. Since I don't know the specifics of the AECS component composition(read that as schematic), I didn't know if this was a possible likely scenario.

 

1 Lucky Texan: You nailed it. I posted this response to a screen I already had open this AM before your post was present, so I never saw you response until post-post occurred( ). Are you lucky because you're in Texas or is there another reason? Just joshing with you!

 

Thanks to all for their reply!