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Wiring harness question

yeti

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Joined
Oct 13, 2010
Messages
797
Location
san diego california
So I looked up a 1g ecu pinout with colors ( attached ) and a good amount of my wires are different colors or lacking pins/stripes.

On another note there’s a - green wire/white pin stripe / red dash -
WIRE just hanging not connected to ecu at all, the pin out says this should be my idle switch or tps sensor, two things that would cause my idle to surge.

So I checked the pin location and there are wires there still plugged in, also a different color that indicates on the pin out.

But the idle switch and tps sensor wires have been molested, still seem to be connected and working ( visual )

Last but not least my knock sensor is consisting of 3 different wires being spliced into one ecu pin. TWO large brown With white pin stripe , and one small black with red dashs wire. ALL going into the original stock white knock sensor wire.

What to do? Where to start?

How can I check if my knock sensor is working properly? ( I have it set to boost gauge on Link and it flashed every now and then on my shitty tune )

How can I check if my tps or idle switch are working properly? The guy who tuned my car was mentioning the isc or tps something was not responding to adjustments on Dsm link.

My bad for all the questions is such a short amount of time, any help is greatly appreciated , also attached is the ecu pin out I followed








<img src="/ubbthreads/images/graemlins/worthy.gif" alt="" /><img src="/ubbthreads/images/graemlins/worthy.gif" alt="" />
 
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yeti

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Joined
Oct 13, 2010
Messages
797
Location
san diego california
From what I can see half of that manual is missing, is the way to fix this issue to physically trace where each wire is going? And or run new wire from the sensor on the harness or where it’s broken to the ecu.

The fact the colors are different is that just a thing from car to car? What 3 wires combined could be give me my knock sensor reading? As that’s working, I think, it’s been tuned on this knock sensor system multiple times.

Just a bit overwhelmed. Gonna try to fiav and isc delete and hopefully the idle surge goes away but at this point I doubt it.
 

CutlassJim

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Jul 17, 2006
Messages
1,694
Location
Manchester, NH
A lot to unpack here.

I prefer to use the diagram from ECMlink

PAH!

The wire hanging out in no man's land seems to be coming from the engine side of the harness and you say the TPS and idle switch seem to be intact at the ECU and judging by your photo's I agree. The green/white as the idle switch was only for the 90 model year. Should be straight green for 91+ and it appears to be hooked up via the ECMLink diagram and your photos. Looks like it may be the MAF reset. No idea why that would be cut but grab a meter and check if that's it. Are you running a MAF?

The large brown/white isn't a "wire" by itself. It's a shielded wire or twisted pair. The outer braids are tied together and grounded via the black wire to shield the internal signal wire from noise. These will be your knock and O2 signals as they are very important and susceptible to EMI.

Looks like your knock sensor wire has the tap on it and the O2 wire is cut completely. No bueno. You probably get CRAP gas mileage. Hook that back up ASAP.

You mention ECMLink. If you have it get a laptop and log IMMEDIATELY. Unclick everything so it's not so cluttered and just look at "Idle Sw", "ClosedLoop", "FrontO2", "ISCPosition", "ThrotPos"

At idle you want the idle switch and closed loop to be 1 with your front Os (Usually blue) cycling up and down with your ISC position cycling around 30 and throttle position at %0

Any of the above being off will cause the car to not idle correctly.

I would do all this before the block off.
 
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CutlassJim

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Here is a log of a man with a dead front O2 (the blue line) and his ISC position is too high.





But he is still in closed loop and his TPS and idle swtich are working correctly
 

yeti

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Joined
Oct 13, 2010
Messages
797
Location
san diego california
Ok so I did my best of rebuilding the o2 sensor plug (harness side ) and attached it to the universal Bosch o2 sensor.
I think I wired that correctly. ( heater wires are power and ground correct?)



And then disconnected my WB input to o2 on ecu and replaced it with the stock white wire to ecu.

While testing the o2 sensor on ACC I got no response from holding a lighter in front of the sensor for about 20seconds.

I’m gonna try to swap the two white wires as I believe they are power and ground with my red and black wires from harness, if I get no response from o2 after test drive tomorrow. I also have a Bosch direct fit coming in by tomorrow.

If any of that makes sense to anyone.<img src="/ubbthreads/images/graemlins/bawling.gif" alt="" />

Also My WB sensor is broken flashing 7.4 so I have a new one otw to replace o2 sensor all together if I can’t get this stock o2 figured out.

Just figured it was good to try and fix that anyways.

Also here’s some logs I posted up on ecmlink

click
 

CutlassJim

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Jul 17, 2006
Messages
1,694
Location
Manchester, NH
About 5 years ago on my current car when I was fixing up the harness I was able to source a perfect condition 8G Galant plug and I run a 2G DSM front O2 sensor. Makes it nice to buy a nice cheap off the shelf O2.
 

yeti

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Joined
Oct 13, 2010
Messages
797
Location
san diego california
Got the o2 working now,

I didn’t save the settings to ecu on link so it was still trying to simulate NB with no signal.

I need to adjust tps still but here’s a pic of a idle log
 
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iceman69510

Turn Right Racing
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Mar 5, 2001
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10,883
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Michigan
Quoting CutlassJim:
About 5 years ago on my current car when I was fixing up the harness I was able to source a perfect condition 8G Galant plug and I run a 2G DSM front O2 sensor. Makes it nice to buy a nice cheap off the shelf O2.



I wired mine up the same way, and it worked great especially since I have a 2g O2 housing (2g O2 sensor is a bit longer harness length). The square style 4 pin connector on the 2g is pretty standard going forward on most Mitsubishis. Used in many other engine room locations too.
 

yeti

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Joined
Oct 13, 2010
Messages
797
Location
san diego california
OK

So I’m running SD do I need to reconnect the maf reset? I don’t see any open ports in my ecu that it could go to.

Also I’ve got the tps set at .55volts at 0% is that good enough or should I pop TB OFF and adjust tps physically?

O2 is all wired up/working and electrical taped so I’ll leave it until I can find a pigtail with sensor.
 

yeti

Well-known member
Joined
Oct 13, 2010
Messages
797
Location
san diego california
Oh also a new fun fact I realized. I only have headlights when engine is running. And the brake lights &amp; side markers get lit up when hitting the clutch

This is not a new problem just one I’ve failed to mention, it’s been like this since I bought the car
 
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