Advanced 12V Starter problem; ECM dropping voltage?

[deadpool]

The 12V starter has never worked in my 2000 MT A/C Insight. Problem: No crank (turn key, no action; no click etc. Instrument lights do come on). I've been running through some diagnostics. The car has always started fine with the IMA battery; except when IMA/CEL was on for an extended period of time and the IMA battery depleted. I've had the battery disconnected for a few days while I've been doing some interior work and now the IMA battery registers empty so the car isn't starting with the 12V or IMA.

I've checked (with IMA battery in OFF position):

-Ground wires. Air box ground was broken; all grounds were replaced with 4 gauge cable.

-Removed starter, disassembled, cleaned and reinstalled. Looked fine and hardly used.

-12V battery is good (jumped starter fine, see next step). Swapped with a new MT34 and no change.

-Applied 12V directly to the starter solenoid and it engaged; sounded alright.

-Jumped clutch switch with a paperclip, no change.

-Checked fuse 9 7.5A, worked fine

-Tried starting with BCM connectors disconnected (and IMA battery switch off); no change.

-Verified that the green immobilizer key warning on the instrument cluster functions correctly; replaced the bulb with a known working bulb. Green key does NOT come on when trying to start. So I assume it is not a problem with immobilizer system. Tried 2 master keys and 1 valet, no change. Tried 2 Honda keys from other cars but they won't turn in ignition, so can't tell if green immobilizer warning will come on.

-Verified (with test light) that START position gets voltage to BLK/WHT wire at ignition switch.
-A24 in ECM gets a bright test light in START position. A1 gets a dim test light in START position. I'm assuming this is my problem. How does the ECM ground? I've been testing it unbolted from the car


Questions:
*Can I start the car (and drive it normally) by simply turning the key to position II and applying 12V to the starter with a jump cable?

*What is up with the ECM?

I am limited to a test light. I have access to a fluke/voltage meter but am not very familiar with their usage. I would rate my mechanical ability at a 7.5/10.

Main diagnostic I've been following: Insight manual, wiring PDF, page 82

[deadpool]

Additional Information: Just tried the starter cut relay for kicks.



I assume that the center relay (circled) is the starter cut relay. I switched it with the bottom relay (same size, different markings- .06t vs .06x) with no effect.



Hooked the test light up to the center relay slot. The two circled female connections for the relay lit up brightly when the key was turned to the on position. Guess I'll try to figure out if I can connect a jumper wire to the relay slot and see what happens.

[deadpool]

Hahaha alright making progress still; when backprobing the starter relay it began to click while grounding at the blue/white A1 ECM wire. So I've grounded the A1 ECM connector directly to the chassis with a jumper, and now have power all the way to the BLK/RED wire coming out of the starter relay under the dash. Now I suppose I have a break somewhere between it and the starter solenoid because I am still not getting power at the solenoid. Still wondering what the problem is with the ECM ground.


^Results before grounding the BLUE/WHT wire. After grounding that wire I am now getting power at the BLK/RED wire when turning key to position III.


This is where I currently am:

Does anyone know where I can find a wiring diagram to trace how the BLK/RED wire connects to the starter solenoid?

[deadpool]

I'm now at the point where I've chased the white/black wire from the starter solenoid into the car. I believe it connects to a blue connector under the dash, and the mating connector has a black wire with thin yellow stripe and silver dots on it. This black/yellow wire looks like it goes to the back of the car, and possibly exits via the fuel pump cover.

The BLK/RED wire coming out of the Starter Cut Relay also connects to a BLK/YLW wire. I believe I chased this wire out of the car, where it exits into the drivers wheel well, and goes to the front driver corner under the hood to the fuel cut relay.

So any help would be greatly appreciated at this point. At least some progress was made. For some reason the ECM wasn't grounded; after grounding pin A1 at least the starter relay clicks. Now I just have to figure out why the starter solenoid is not getting power to the black/white wire. Possibly the ELD? Haven't found a testing procedure for that yet.

[deadpool]

I've traced the solenoid wire to the fuel pump. The wire after the pump isn't getting power with key in position III. I've traced the wire after the starter relay to the fuel cut relay under the dash. I'm not sure how to test this; but I assume that if it was bad the car wouldn't have run when started by the IMA system. I tried a relay from under the dash in its place (no idea if same functional style) without change. I'm not exactly sure how to trace the wire from the fuel cut relay to the fuel pump


Currently this is my situation:

[AbCaRed00]

Originally Posted by deadpool

Does anyone know where I can find a wiring diagram to trace how the BLK/RED wire connects to the starter solenoid?

Here's a spreadsheet of hyperlinked engine codes for the most part with some useful additional hyperlinked info like wiring diagrams and electrical locations.and links to stickies. Hope that helps.
Electronic Troubleshooting pdf.s are hard to search online so maybe download from the stickies at head of the forum and search for "obdII codes.pdf' as the index.

[deadpool]

Applying 12V to the green/yellow Fuel Cut Relay gets a "click" from the relay.

Thanks AbCaRed, I have the downloaded PDF Manual from this site; unfortunately I don't think it supplies the information I'm looking for.

I'm assuming that there's a bigger cause which these little problems are stemming from. I'm not familiar with how the IMA/12V starting system interacts; I believe the IMA system normally shuts the 12V starter system off for daily driving. I'm guessing there's a problem with that switch which is causing my current no start (and I'm simply bypassing each step of this "shut down" process).

[Mario]

Just to cover the basics... you're holding the key in the start position for at least ten seconds, right? It's usually quite a while before the car decides to give up on the IMA system and start from the 12v.

Also, because it is possible to push-start a manual, I assume the only thing required to make the car run normally is to have the key in the run position and get the engine turning. I don't think the starter is more complex than "apply 12v and spin", so I assume that would work.

[AbCaRed00]

Originally Posted by deadpool

I'm assuming that there's a bigger cause which these little problems are stemming from.

Could be mice as an afterthought, they've been known to chew wires in the IMA/IPU system.

[deadpool]

Thanks Mario, that's what I was assuming about the direct voltage. Yeah, I've tried the 30 second key hold, the quick cycle, the BCM disconnected, IMA switch on/off, praying to Soichiro himself

Good point about the mice, I did find one mouse dropping while checking ground 101 & 102 on the engine block, but have yet to find any chewed on wires/wirelooms or nests etc.

It was also involved in a serious accident with a previous owner ~8-10 years ago (I believe passenger side) but I haven't experienced any other adverse effects from it (car tracks straight, tires wear evenly, etc.) Right now I have the interior out and everything looks pretty decent, no paint color changes, ugly welds, etc.