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Hypermiler
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3,650 Posts
Discussion Starter #1 (Edited)
Not much of a mod, nor very technical. I went 'gas only' on my silver due to a pack issue (1449-74).
I'll provide some notes and general info for those who may need or wish to do the same.

I followed Jeff's HydridAutomotive procedure here. Easy procedure to follow and worked on first try.
It
CEL and IMA lights remain on. In some states, the car will not pass inspection with a cel. Here in PA it's ok.

--- Edit: post 116 on page 12, pulling the 4 plugs on the front of the mcm gets rid of the ima light.

With this method, the dc/dc remains active to keep the 12v charged.
The 12v starter up front cranks the engine for start up. Sounds weird hearing that instead of the smooth ima start ups.
Definitely need a good 12v up front, especially for cold weather starts. If in doubt, have it load tested at your local Autozone or such.

I monitor 12v voltage on my obiic&c. If you don't have an obd, there are inexpensive volt monitors available at Walmart, Autozone, Amazon and such that plug into the power outlet.

Engine idles a bit rough without the IMA smoothing out the idle. Runs / sounds normal at higher rpm.

Rpm > 4k runs motor/generator voltage over 240 volts. Dc/dc shuts down, brake/batt lights come on. 12v not being charged. Post #17 has pics.
At about 3500 rpm and below the motor/generator voltage drops below 180v, brake/batt lights go out (takes a minute or so), dc/dc back in
service, 12v being charged again.

Update: Tank mpg at 69.3 and 579 miles. 4 bars left on fuel gage. See post #49 with pics. It did better than I thought it would for gas only.

Update: 2nd tank on gas only: 69.5 mpg (Oct)

Update: 3rd tank on gas only 70.8 mpg (Nov.)

Update: 65.5 (late Nov. tank)

December 66.0, tank

Jan (early / very cold) 60.8, tank

Feb (early) 65.5, tank

Feb (late) 67.9, tank

Mar 69.0, tank

Mar (late) 72.6

Apr 70.7, tank

May 78.4, tank

July (early) 79.4, tank

July (late) 80.8, tank

12 month rolling average while on pack bypass is 63.8 mpg commute to work, 80.2 commute to home, round trip avg 72.0
 

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Hypermiler
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3,650 Posts
Discussion Starter #2 (Edited)
Lack of power and SLOW acceleration immediately noticeable. I allow LOTS of room for getting out onto the highway.

I run the rpms up more than I was accustomed to. About 3k to 3500 before up-shifting. That puts me back at about 2500 rpm in the next higher gear allowing better power range. (I stay under 4k rpm simply to avoid the annoying brake and batt lights)

Inclines require lower gears than I'm used to. 2800 rpm and higher to enable vtec is very helpful.

Downhill running with no regen braking requires lower gears too, so I don't wear on the friction brakes too much. ( I really miss the regen braking)
 

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Hypermiler
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3,650 Posts
Discussion Starter #3 (Edited)
No lean burn or auto stop. :(

Mpg is surprisingly still decent. 67 mpg on commute to work tonight. The commute is in my signature. I run about 5 mph under speed limit on 70 mph highway.

The mountain climb has a truck lane, just right for Insights.

FAS on the MIMA controller still works, but without IMA there is no auto-start when going back into gear.

Attempting to restart the ice with the key did not work at first. I had to 'key off' then restart. I won't do that anymore, since the steering locks with key off.

EDIT: from page 5 post 349 of this thread, I brought forward the mpg for near complete tank of fuel. 69 +, not bad for no IMA. Still 4 bars on the gage.
 

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Hypermiler
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3,650 Posts
Discussion Starter #4 (Edited)
Across the next few days I will try various parameters on the obdiic&c such as:

mdm amps, volts, temp; dc/dc temp, and dc/dc inhibitor status.

btw: obdii indicates 65,500 deg F pack temp with my pack bypassed.
 

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Hypermiler
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3,650 Posts
Discussion Starter #5 (Edited)
After start-up, the ecm side of my obd goes to all x's, I think due to the 12v voltage dropping during ice start. Restarting the obd restores the data.

Hoping I could get lean burn again, I tried to trick the car into thinking the SOC was higher than 30 by toggling the obd for an soc of 40, 60, or full (no LB when soc is < 30), no go :(
 

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After start-up, the ecm side of my obd goes to all x's, I think due to the 12v voltage dropping during ice start. Restarting the obd restored the data....
That happened to me, too, when I had my pack bypassed. I also figured it was because of the 12V battery voltage drop - either that or it's just the way the auxiliary starter motor is tied-in to the system. I was starting the car off a 10 cell NiMH battery though (10 cells from Insight sticks), and they weren't very good either. I think voltage dropped to about 7.8V when starting, similar to yours... Pretty amazing that old Insight cells could handle the starter motor - I must have started it at least 50 times before I got my pack back in and IMA up and running...
 

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OBDIIC&C ECM side failure when pack bypassed.

That's an interesting phenomena and is being caused by the ECM resetting when 12v cranking rather than the OBDIIC&C.

When ign is turned on the OBDIIC&C sends a special command to the ecm to put it into honda extended data mode. The ecm then responds to special data requests we are familiar with. If the power to the ecm is disrupted/drops below a critical level/interupted the ecm forgets it was in the special mode and then doesn't respond to the obdii requests..

Resetting the obdii causes it to resend the special mode change command which sorts the problem..

I will tinker with the obdii firmware and resend the mode change command if the ecm stops responding....
 

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Lack of power and SLOW acceleration immediately noticeable. I allow LOTS of room for getting out onto the highway.

I run the rpms up more than I was accustomed to. About 3k to 3500 before up-shifting. That puts me back at about 2500 rpm in the next higher gear allowing better power range. (I stay under 4k rpm)

Inclines require lower gears than I'm used to. 2800 rpm and higher to enable vtec is very helpful.

Downhill running with no regen braking requires sooner downshifts so I don't wear on the friction brakes too much. ( I really miss the regen braking)



Above 4k rpm, the batt and brake lights on the dash come on. dc/dc is disabled because the mg voltage is to high for the dc/dc. I'll set up the obd to observe that and post it.

The above lights go back out after the rpms drop below about 1200.
At what RPM is the rev limiter working? If it is lower than standard, the car is in what I call a limp home mode, and power is well down in part because of that.
 

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Julian, I think he's just choosing to stay below 4k RPM... which is pretty limiting.

They spaced gears 1, 2, and 3 about as far apart as they could while still keeping it possible to stay 'in VTEC' the whole time. So, for reasonable acceleration, I suggest reving to about 5500 in first and second before up-shifting. You don't have to press the gas pedal down very far, but you need the revs if you're trying to accelerate.
 

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No lean burn
With my burnt out BCM and IMA battery turned off, my can get into learn burn with no issue.

I got drove 62miles and got 67mpg at ~65mph.
 

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What doesn't seem widely understood is that with the IMA switched off and without certain specific modifications undertaken, the petrol engine is in a lower power mode.

In my car that was most obviously indicated by a lower rev limit.

To find out quickly and easily if your car engine is in a lower power mode because it senses that there is an issue, check what the rev limit is.

I am confident that lots of people who complain about a major lack of power with the IMA turned off are in this limp home mode. I don't know for certain, but I suspect that this mode retards ignition timing, so reducing power.
 

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What doesn't seem widely understood is that with the IMA switched off and without certain specific modifications undertaken, the petrol engine is in a lower power mode.

In my car that was most obviously indicated by a lower rev limit.

To find out quickly and easily if your car engine is in a lower power mode because it senses that there is an issue, check what the rev limit is.

I am confident that lots of people who complain about a major lack of power with the IMA turned off are in this limp home mode. I don't know for certain, but I suspect that this mode retards ignition timing, so reducing power.
Interesting, I've never heard of this. Is there a way for owners with a disabled IMA system to turn limp mode off?
 

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...
Above 4k rpm, the batt and brake lights on the dash come on. dc/dc is disabled because the mg voltage is to high for the dc/dc. I'll set up the obd to observe that and post it.

The above lights go back out after the rpms drop below about 1200.
Hmm, in my 2006 (currently with the IMA system not working but not switched off), only the battery warning light, not the brake warning light, comes on above 4k rpm.

My IMA and CEL lights are on continuously due to the commutation sensor problem.

Similar behavior was observed in my recently-acquired 2001. Driving it back from Denver, a P1449 code triggered the IMA and CEL lights, and the battery, but not brake, warning light illuminated when pushed over 4k rpm.

Is the brake warning light above 4k rpm a common observation when running the car with the IMA battery switch off?
 

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Hypermiler
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3,650 Posts
Discussion Starter #15 (Edited)
Gathered some data today and some pics. I'll post below.

Julian: I've not heard of the rev limiter. And I don't have any obd data on ignition timing from before the pack coded. I did rev the engine today (sitting in neutral) to gather MDM info. No problem going to 4200 rpm to trigger the brake and batt lights. I'm a conservative dinosaur on the revs, I've never ran rpm's up out of caution. Today I think I hit 4700 a couple times while trying to feather the throttle for a photo. More below.

Tryingbe: interesting on the lean burn. All that I've read (and heard) is when the pack is under 30 soc (or disabled), those folk did not have lean burn, and nor do I. I've observed this both my mt's when soc is below 30. I did have some surprisingly good mpg on the commute to/from work with the bypassed pack: 67 going up, and 83 coming home.

Davenm: Yes, all that I've read and heard is both the brake and batt lights come on with high rpm due to the dc/dc shutting down. More below.
 

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Hypermiler
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Discussion Starter #16 (Edited)
1st pic: key on, engine off, prior to cranking for start-up

2nd: during cranking, 12v drops to 8v, ecm side of obd drops out. Toggle down for a fan or soc status and push for restart restores right side of obd.

3rd: engine at idle speed. typical IMA and cel with disabled/bypassed pack.

4th: 2k rpm, 108 volts Mvo
 

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Hypermiler
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Discussion Starter #17
1st pic: 4k rpm, no problem getting there, lots of throttle left. No brake/batt lights yet.

2nd: 254 volts Mvo, 4200 rpm.

3rd: 4200 rpm, brake and batt lights.

The dc/dc shuts down somewhere around 250 volts triggering the brake/batt lights. I also noticed the obd back light and dash lights dim a little bit when this occurs.
While gently increasing throttle and rpm, the MDM (Mvo) voltage steadily increases.

When easing off the throttle and slowing the engine, the MDM voltage did not drop correspondingly. It held in the 230-250 area for some time (about a minute or so) then dropped suddenly to a corresponding voltage for that rpm. (capacitors in there somewhere ??)

It appears that the brake/batt lights go back out when MDM voltage drops below approximately 180 volts, or about 3500 rpm + / - a tad, and including the time delay, indicating the dc/dc is back in operation again. I noticed the dash lights and obd backlight brightened a bit.

MDM voltage would then drop with continued reduction of rpm.

Again, not very technical, but nice to know what's going on.
 

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Don't see a real issue since your battery should not discharge much. Im guessing you can trick the computer to not turn the lights on somehow.
 

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Yes, make the ECM think the MCM is saying "all ok". Search the youtubes for "Honda Insight IMA bypass"
Does this also keep the dc-dc converter from shutting down? If so, wouldn't that potentially cause damage to converter from excess voltage above 4,000 RPM?
 

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Does this also keep the dc-dc converter from shutting down? If so, wouldn't that potentially cause damage to converter from excess voltage above 4,000 RPM?
No it doesn't, you still have the dc-dc shutdown issue. I suggest you look at the meanwell psu option.

My nephew is now driving round in my imaless car (meanwell equipped car) with ECM fooler without issue....
 
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