[diyengineer253]

Hello,

2000 Honda Insight here (MT/AC). Long story short charged the battery back up and it seems to be doing alright, even turns my car on. User before me cut two wires, and I’d like to return the car to stock config.Help identify please? In case I have to bypass again I’ll use switches. They appear to be a white and a green wire.

 

[ericbecky]

Just hook those two back up again.
Green to green.
White to white.

They are not required for bypass.

For bypass simply unhook all
connectors that go to the BCM. (Computer on top of the pack on the left)

 

[diyengineer253]

The car is currently bypassed, so if those wires don’t bypass it, how is my battery getting charged up? Been driving it for a year or so now? Maybe the connector is slightly unplugged and I just haven’t noticed?

 

[diyengineer253]

Just hook those two back up again.
Green to green.
White to white.

They are not required for bypass.

For bypass simply unhook all
connectors that go to the BCM. (Computer on top of the pack on the left)

Thanks Eric. Let me check it out. Just finished replacing my ground straps for 2nd time. Also got sick of using my starter and replaced it as well, so figured might as well see if she works!

 

[jeffffej]

Perhaps @Natalya will chime in. When I had my blue Insight I learned that it had been determined by someone somewhere that one (or was it two?) wires could be cut to allow the car to operate better. It was above my pay grade but it seemed right. Cut them on mine, it performed fine without a battery, then once I installed IMA it still performed perfectly.

 

[diyengineer253]

After pulling the negative battery wire off, how long does it take driving around for the IMA battery to show a charge? I know it’s charged for a fact, so it should show something on the gauge right? Is there a delay?

 

[eq1]

^ If you're talking about pulling the 12V neg cable to reset stuff, and having installed or otherwise 'un-bypassed' the IMA pack, then it shouldn't take much time at all. Sometimes you don't even have to drive, the BAT gauge will repopulate with just the key ON II... So, the answer is, you should see the BAT gauge lighted bars almost immediately, certainly once you start the car.

User before me cut two wires, and I’d like to return the car to stock config.Help identify please? In case I have to bypass again I’ll use switches. They appear to be a white and a green wire.

The WHT/GRN wire controls toggling into DCDC low power mode (~12.2V vs. ~13.85V). With it cut it won't go to 12.2V. The GRN/BLK wire controls whether the Motor Control Module computer can disable the DCDC. With it cut it cannot disable the DCDC. The former mod is usually done to keep the 12V battery charged higher on average. The latter mod doesn't really help much and should be reserved for special circumstances.

 

[diyengineer253]

^ If you're talking about pulling the 12V neg cable to reset stuff, and having installed or otherwise 'un-bypassed' the IMA pack, then it shouldn't take much time at all. Sometimes you don't even have to drive, the BAT gauge will repopulate with just the key ON II... So, the answer is, you should see the BAT gauge lighted bars almost immediately, certainly once you start the car.



The WHT/GRN wire controls toggling into DCDC low power mode (~12.2V vs. ~13.85V). With it cut it won't go to 12.2V. The GRN/BLK wire controls whether the Motor Control Module computer can disable the DCDC. With it cut it cannot disable the DCDC. The former mod is usually done to keep the 12V battery charged higher on average. The latter mod doesn't really help much and should be reserved for special circumstances.

Good to know. I’ll hook both back up and see if it gives me any issues.

 

[retepsnikrep]

Reconnect the green/black wire but leave the white/green wire unconnected for a slightly better charged 12v battery.

Even in stock form cutting the white/green wire is sensible.

 

[Natalya]

Good to know. I’ll hook both back up and see if it gives me any issues.

As Peter said, just hook up the green and black wire. Leave white/green wire cut. All Insight owners (whether IMA is bypassed or not) should cut the white/green wire.

More reading and a video:

Mod to keep 12 volt battery charged

Howdy folks, here's a video showing a quick, simple modification that prevents the ECM from controlling whether the DCDC is charging the 12 volt battery. This means the DCDC will always keep the 12 volt rail at 14.x volts when the car is running (or in autostop), unless the IMA battery is...

www.insightcentral.net

 

[diyengineer253]

Hello,

The car was starting with the electric motor vs the electric starter before after I had it charged up via grid charger. (A week passes, replaced all new grounds and power cables, and fixed cut wire per recommendation) It tried to start up with electric motor (whirling noise) but went to backup after a few seconds (carhad been sitting for a bit so it took some time. The ima battery level gauge still shows nothing (after taking a full charge a week or so ago) and I’m getting this code. Would this result in it not showing my battery level?

 

[retepsnikrep]

That code stops the IMA working so the car can't force charge when running and do a positive recalibration to determine the SOC and fill the bars on the gauge.

If the IMA battery voltage is high enough ~170V+ or above at switch on then it might do a positive calibration without the engine running if the ign is left on for a few minutes.

 

[mudder]

Someone linked to this thread and I figured it was worth explaining what these signals do (for others reading it later):

Cutting the WHT/GRN wire heading to the DCDC converter prevents the ECM from placing the DCDC in "12.x" mode. Specifically, after cutting the WHT/GRN wire, the DCDC will continue outputting 14.x volts, even if the ECM wants the DCDC to output 12.x volts (theoretically to improve MPG under certain driving conditions). I always recommend cutting (only) the WHT/GRN wire.

...

Cutting the GRN/BLK wire heading to the DCDC converter prevents the MCM from turning off the DCDC. I do not recommend cutting the GRN/BLK wire unless you are stranded and need to get home. Cutting the GRN/BLK wire should be a temporary ordeal. If you cut the GRN/BLK wire to get home, I also recommend turning off the IMA switch.

More details on cutting the GRN/BLK wire:
With a 'good', 'ok', or 'weak' IMA battery:
-the MCM will only turn the DCDC off when the key is ON, but has not yet moved to 'START' during this drive cycle.
-At all other times, the MCM allows this line to float (hence the DCDC converter is enabled).
-cutting the GRN/BLK wire can cause a "bypass contactor stuck on" CEL, particularly when you quickly turn the key off and back on.

With a 'really bad' IMA battery:
-the MCM will turn the DCDC off (i.e. pull GRN/BLK low) if the HVDC rail fails to stabilize to any decent amplitude after the car starts. Specifically, if the IMA battery is so weak that different engine RPMs cause wildly different HVDC voltages, then the MCM will turn the DCDC off, so as to alert the user that the DCDC can no longer reliably charge the 12 volt battery (a safety issue, particularly when ABS engages). Note that if you get to this point, the IMA + CEL lights will have already been on for months, giving you plenty of time to fix the failing IMA battery. Having exhausted waiting for the fix, the MCM finally gives up and disables the DCDC entirely, so as to force you to fix the problem...

...but if you want to keep ignoring it, you can cut the GRN/BLK wire, thus preventing the MCM from being able to turn off the DCDC. Note that no other computer in the car is able to turn off the DCDC (remember: the ECM can only select the output voltage - 12.x or 14.x - not disable the DCDC entirely).

So then, if you get stranded with a dead DCDC due to a really bad IMA battery, then (temporarily) cutting the GRN/BLK wire heading to the DCDC will allow the DCDC to charge your battery, but only as long as the HVDC rail voltage is within the DCDC's operating limits. Specifically, when the engine is idling or above 4000 RPM, the DCDC will disable if the IMA battery is very bad and you've cut the GRN/BLK wire.

I do not recommend long term operation with the GRN/BLK wire cut.