[Gasoline Fumes]

I can't find anything wrong with the MOTFSA connection. What I've recently noticed is that the P1644 pops up when I unplug my Bluetooth adapter after setting the OBD2 readiness monitors (except EVAP). It will eventually give me the P1644 no matter what, but doing anything with the OBD2 port seems to trigger it immediately. Some kind of interference? I was only using one of the three filter capacitors from the MDM. I hooked up all three and the result was the same. Then I added another one of the 1750 µF capacitors to filter the Arduino's power input, which didn't help either. Should I suspect the Arduino or ECM at this point? I have two other ECMs that I can try. Different part numbers, but all from 2000 Insights. Thanks in advance for any advice!

I think I fixed it!!! 😀😀😀😀😀🎃

Looking at my Electrical Troubleshooting Manual, I noticed the IMA/Arduino shares ground #101 with the OBD2 plug. G101 doesn't look terrible, but what else could I try? Moving the Arduino ground to the chassis near the Arduino seemed to solve the issue. I can plug/unplug the OBD2 port without triggering a DTC! Yeah, I'll clean up G101 someday and hopefully fix a few other issues! G101 seems to be for all the important stuff. It's between the valve cover and MAP sensor, in case anybody was wondering. Stupid Insight grounds!

 

[mudder]

Glad to hear this troubleshooting step resolved your issue...
...but I will caution you against connecting to chassis ground long term, as this could create a ground loop between the (low noise) GND_ENG & (high noise) GND_CHASSIS signals. My recommendation would be to tap off GND_ENG somewhere else in the wire harness (that's not damaged).

 

[FormulaLosAngeles]

I have been looking for a lead on ima bypass plugs for scratch build harnesses.
these links look good
at the moment I dont have access to the pin width choice to measure
(the two pin power plug is rumored to be used on honda and subaru air pumps but no lead yet.)

16-Way Connector Kits | Corsa Technic - Sumitomo

Motorsport electrical products: OEM and hard to find terminals and connector kits, wiring, harness supplies, tooling, and sensors for modern and vintage motorcycle, automotive applications. Easy online shopping, low cost shipping options, to expedited around the world. We accept Paypal and...

www.corsa-technic.com

Sumitomo HE 050+187 Hybrid Unsealed Motorsport Connectors - Corsa Technic

Motorsport electrical products: OEM and hard to find terminals and connector kits, wiring, harness supplies, tooling, and sensors for modern and vintage motorcycle, automotive applications. Easy online shopping, low cost shipping options, to expedited around the world. We accept Paypal and...

www.corsa-technic.com

 

[FormulaLosAngeles]

here are some pics in pinwidths of plugs in the batterybay with a ruler, that may help to identify a scratch build plug order.
(Addressing the plugs in front of the stick shift is another place for a bypass cable of expediency not studied yet)

 

[mudder]

My recommendation (for now) is to just buy a replacement IMA harness directly from Honda... it's $120, which gives you all three connectors you need with the correct wires already installed. Not sure what your time is worth, but for me it's a no brainer: I'd buy the cable every time from Honda.

 

[FormulaLosAngeles]

I cannot find a part number for the harness in example links below.
I do dread crimping and inserting pins. I would like to save my disabled IMA parts for possible future use, although I suppose attrition used parts might be a source.

Honda online store : 2002 insight ima wire harness parts

eStore by American Honda

estore.honda.com

2001 INSIGHT Hatchback DX (A/C) 5-Spd Man - 49 State Emissions (KA) | Ima Wire Harness - Bernardi Parts Honda

www.bernardiparts.com

IMA Wire Harness for 2001 Honda Insight | Honda Factory Parts

www.hondafactoryparts.com

 

[mudder]

1N000-PHM-010
As of this writing, it's $128.59 on hondaautomotiveparts.com

 

[Chuoiz]

I dont mean to undermind mudder but the connectors are available so no need to hack oem full harnesses if you want to make one from scratch. I have a few set of these connectors available if someone wants to get them for small fee. As for the 2 pin connector that attaches to the fuse, oem g1 are 1F630-PHM-003, or alternately you can purchase (1F630-PZA-003) which is for hch1 but basically the same connector but orange and half the price. Another note I would like to add is imabypass arduino code did not get me lean burn but imabypassleanburn code did fot my 02 MT for reference.

 

[tryingbe]

You can make reversible modification easily on the IMA harness.