What is this shenanigans going on in my engine bay?

[Pathofinder]

Basically I noticed some half rigged wiring going into my battery side fuse box today, with a relay mounted on the fender wall on the passenger side, and 2 wires going into the fuse box. Im quite curious what it is doing!!



You can see 2 wires off the bottom of the relay are grounded right there. The red wire off the relay goes to the blue relay on the right, a black wire from the relay went to the brown relay


For reference heres a pic of the fuse cover, the relays that are being tapped into are EGI and fuel pump 2



I disconnected the brown relay only to see were the wire was going, and it lead to a terminal on the right side of the relay.

What could this possibly be for?

[Towncivilian]

Aftermarket alarm/immobilizer?

[fueler]

cut the wires and see what stops working

[Buzzman]

I don't have an answer to your wiring question, but following your posts, I can't believe all the problems you've had with this thing. I feel for ya.
Is there any way you can get some kind of warranty or compensation back from your dealer for selling you this lemon?
It's obvious someone messed with the truck before you got it, and made every effort to hide all the problems. I'd be pissed, that's for sure.
Keep us up to date. Good luck.

[Chuck Tribolet]

The EGI also has to do with the fuel pump. It's job is to make the fuel pump NOT run if you turn on the ignition and just sit in the truck. The PO was monkeying around with the fuel pump control systems.

The Bosch relay probably has DIN labeling of the pins. 85 and 86 are the two sides of the coil, 87 is the movable side of the contacts, and 30/51 is the fixed side of the contacts. Trace each of these and report back where it goes (and the wire color
the PO used would be helpful for us to describe what to do), and what pin on where it goes, and the color of factory wire that
goes to that pin.

Page EC-618 of the '01.5 PF FSM discusses this.

Remove the Bosch relay from the firewall, look at the bottom where the wires come in, and tell us w

[Pathofinder]

Thanks for the help, I will check the wires and exact location and numbers in the morning.

I fear this modification had to be done to keep the truck running for some reason. Like I said I pulled the brown relay when I took those pictures, and the wire that was stuck into the bottom of the relay just kind of sat there when I pulled the relay off, thought I put it back together exactly the same as it came apart.

Sure enough when my husband went to leave for work the car wouldnt start, he said it just cranked and cranked and cranked but wouldnt catch and run, so I think maybe I put the wire back in the wrong spot, and being what Chuck said about it being fuel pump related. That sounds right

I wonder what they are coverring up doing this though...

[Pathofinder]

So as Chuck Tribolet said this is definetely a fuel related "fix", I notice that the fuel pump is no longer priming, and the check engine light no longer illuminated nor will my OBD scanner connect with the car, it just reads error

I pulled the Bosch relay top off and noted the wires. # 86 and # 87 are grounded to the body. # 30 goes to the EGI factory relay and # 85 goes to the factory Fuel Pump 2 Relay.

Just a note also we bought another bosch relay and tried replacing that just plugging it into the already wired base the the previous owner must have wired in, but no change.

Appreciate all the help I can get on this guys, this is some shotty arse work, and I would love to know why this wiring is even in there and necessary...

[Pathofinder]

Well I got the truck running again, I did indeed have the EGI "ghetto wire" placed in the wrong terminal pin from when I disconnected it to see where it was going, placed it one pin back and the truck fired up

This is still not really acceptable and I would love to delete this unnesecary relay and ghetto tapped wires

A few things I noticed that may help solve this, when I had the wire from the EGI relay disconnected (so I guess the whole circuit they added was not working)

-the fuel pump was not priming
-the check engine light was not illuminating

There may have been more things, but those were the obvious things I noticed when trying to start the car without those wires connected.

I appreciate the help ALOT guys, thank you

[Chuck Tribolet]

I pulled the Bosch relay top off and noted the wires. # 86 and # 87 are grounded to the body. # 30 goes to the EGI factory relay and # 85 goes to the factory Fuel Pump 2 Relay.

Where on the factory relays do 30 and 85 go? What color wire on the factory side, or pin number, or something?

[Densetsu]

Edit: This is my theory, I was bored at work today. I made some assumptions as to what pins the Bosch relay connects to on the Fuel Pump 2 and EGI relays, and provided my reasoning below. It'd help a lot if I could get confirmation of these assumptions from Pathofinder.

Also check EC-24 and EC-25 in the FSM (click here), these are circuit diagrams of the entire engine control system. The EGI relay is the ECM relay in this diagram. What does pin 87A on the Bosch relay connect to, anything? I suspect nothing, just want to confirm.

The coil for the "fuel pump 2" (FP2) relay is connected to the ignition switch and the ground, and is switched on when the key is turned to ON or START. I'd suspect the FP2 coil's ground wire is now connecting to the coil for the Bosch relay, causing the Bosch relay to connect pins 87 (ground) and 30 (an EGI relay pin) on when the key is turned. The contacts on the FP2 relay are connected to (1) the battery and (2) one contact on the FP1 relay. The other contact on the FP1 relay goes to the fuel pump. The coil for the FP1 relay is connected to (1) the ignition switch and (2) the ECM. The ECM can ground that wire whenever it wants, turning on the fuel pump.

(My reasoning: The other end of the FP2 coil is connected to ground. One of the relay switch's pins is connected to the battery. The other end of the switch is connected to the FP1 switch, which is turn is connected to the fuel pump, which then connects to ground. There is just this one circuit in the fuel pump. Thus, it'd make no sense for any of the other pins on the FP2 relay to be connected to ground through the Bosch relay's coil.)

There are two switches in the EGI relay. Both switches have one contact connected to the battery, and the other contact leading to multiple systems. In total, the relay provides power to several systems (as well as supplying power to the ECM on the same circuit): ignition coils, IAVC valve, crankshaft position sensor, MAF sensor, and intake valve timing control sensors. If these contacts were connected directly to the ground in the Bosch relay, the systems would never work. Since the Pathy was running before, I think we can rule out the possibility of the Bosch pin 30 being connected to the switches.

The coil for the EGI relay connects (1) the battery to (2) the ECM. If the ECM grounds out that coil pin, the switches in the EGI relay close and all the systems listed above have power supplied to them. I'd suspect that whoever added the Bosch relay disconnected the EGI relay coil from the ECM, and instead connected it to pin 30 of the Bosch relay. The systems listed will now always have power when the key is in the ON or START position, instead of only having power when pin 26 in the ECM relay says it should.

So, in summary:

They key is turned to ON or START. The FP2 relay supplies power to one side of the switch on the FP1 relay (which may or may not close and provide power to the fuel pump itself: the ECM has to ground the FP1 coil). Instead of the FP2 coil going from key -> coil -> ground, it now goes key -> FP2 coil -> Bosch coil -> ground. The Bosch coil is also activated whe the key is turned, and grounds out the coil in the EGI relay. This means the switches in the EGI relay are always closed, instead of the ECM telling the EGI relay to close or not.

Now, why they would do this? I have no idea. Maybe the ECU is damaged, maybe the harness is damaged, maybe to bypass security as some aftermarket install. I'm not sure. Others can chime in. I can say that pin 26 in the ECM harness is connected to the EGI relay's coil, so if someone has a legend for the ECM harness, it'd probably provide some insight.

But also be aware of one point earlier, in bold above: The EGI coil provides power to pins 110 and 112 of the ECM harness, and possibly pins 6/8 and 7/17 (variable inductor on the IACV valve; not too familiar with the specifics of those). The ECM usually controls the EGI relay, but now it does not. If the ECM tells the EGI relay to open the switch, but the EGI relay doesn't (since the relay's switches are now always closed when the key is on), the ECM might not be prepared to handle a high-amperage current to pins 110 and 112 of it's harness. Which could damage the ECM. I really hope this isn't the cause of why your Pathy isn't running, AND isn't showing the check engine light, AND is giving your OBDII code reader a generic ERROR message. But it could be.

Edit: I see now that you have the Pathy running smoothly, glad to hear. But this setup could still potentially damage your ECM.

[Chuck Tribolet]

I wish I was bored at work. Busy, busy, busy. We posted 4th quarter results recently. The piece of the business I'm in was up about
75% year to year!

I don't think there are two coils in series. That would be unreliable. I think Bosch #85 (hot side of coil) goes to the factory Fuel Pump 2 Relay #5 or #1, both of which are hot whenever the key in ON or START. Where Bosch #30 goes on the ECM relay is anybody's guess. Let's see what the OP posts.

I can guess at three things they were patching around:
Blown fuse 62
Blown fuse 63
Bad ECM relay.

OP: Check fuses 62 and 63. They are in the same box with the relays, rear row, 4th and 5th in from the fender (Check the label,
though). And please tell us where Bosch #85 and Bosch #30 go.

[Densetsu]

Here's my quick circuit diagram now that I'm home. Remember, I'm a programmer, not an engineer, so forgive me for sloppy work.

http://digitalequilibrium.com/images/ni ... _bosch.png

Does anyone know what NVIS/NATS disables when a bad key is put in? I always thought that it cut power to the fuel pump, but can't see that being said in the FSM. Could it be opening the ECM relay's coil circuit (by un-grounding pin 26 on the ECM harness)? This Bosch relay could be a way around it.

[Densetsu]

Also, in my Googling around, I found out that other fobs on my keychain can cause intereference with the NVIS system. I've had very intermittent problems with NVIS not recognizing my key; it'll just turn over without starting, and light up the security light. I have two other fobs on my keychain right next to my Pathy key -- Esso Speedpass and Shell Easypay. Hopefully, keeping those away from the Pathy key will solve this problem.

One positive to this thread!

[Pathofinder]

Wow guys, I cannot believe you put so much thought and knowledge into this, I appreciate it soooo much, Im not going to lie, Im not smart at all when it comes with wiring, especially relays I just dont understand them and I dont think my husband has a grasp either, but you guys seem to. I would LIKE to remove this relay and fix the underlying problem if possible. I read everything you guys posted, and one thing really stuck out to me I thought I should point out.

You said this (below)

There are two switches in the EGI relay. Both switches have one contact connected to the battery, and the other contact leading to multiple systems. In total, the relay provides power to several systems (as well as supplying power to the ECM on the same circuit): ignition coils, IAVC valve, crankshaft position sensor, MAF sensor, and intake valve timing control sensors. If these contacts were connected directly to the ground in the Bosch relay, the systems would never work. Since the Pathy was running before, I think we can rule out the possibility of the Bosch pin 30 being connected to the switches.

When we first got the car, it was throwing SEVERAL codes, every single one you mentionned actually. We replaced the crank sensor, 2 vtc cam sensors, cleaned maf, 1 new ignition coil. BUT we are still ridden with P1110 (some sort of intake solenoid error) and the odd time it throws P0505 (IACV) and you can sometimes hear the IACV clicking and making noise after the car is turned off. P0505 has only been thrown a few times, but is ongoing, I figure because we erase the codes so often without driving it to much.

I will do my best to bring the car to a carwash in the morning as I dont have a warm place to work on the car, and Ill try and decifer exactly which wires going to which pins and report back, as is seems you gentleman are onto something, at the very least I'll have detailed pictures.

Im quite curios, and almost scared, of what this wiring is "avoiding" and why it was added and what doorknob added it

Thank you again

[Chuck Tribolet]

Always P1110 and never P1135? P1110 is the US passenger's side, P1135 is the US driver's side intake cam solenoid.

They can come from:

Bad cam timing sensor.
Bad cam timing solenoid.
Low oil pressure. It will usually throw both codes if this is the problem.

I've had both off and on for four years. I noticed from the snapshot when the codes were pulled that it was happening at full
throttle between 1500 and 2400 RPM. So I don't do that, and I run 10W40 instead of 5W30 oil (thicker oil means a little more oil
pressure) and I can USUALLY keep it away. It's a minor effect anyway so I wouldn't worry about it at this point.

[Pathofinder]

Never P1135 or 45 like when we bought it, I figure the sensors we changed cured that. Only currently throws P1110 and P1165 on our short trips and limited usage of the truck (Id drive it more if I wasnt scared of it breaking down)

Im not to worried about the code itself, but more than this wiring BS might be the cause of it.

I was unable to trace and take pics of the pins this shotty wiring was going to today, there was a good snowstorm and my husband needed the car to take to work instead of the Matrix. I will 100% have the car to myself tomorrow though so I will post back and take pictures.

[ARKQX33V6]

Pathofinder, please take pictures before you play with wires or make a drawing, then when you modify draw your modifications.

Understand relays. Understand grounding. Understand series and parallel. This is a must.

A physical relay has a physical coil that could be the same voltage or different from the control contacts. That coil can be the same voltage but have the coil designated as 12 V but one side of the coil is grounded or you must ground it or when installed on the sheet metal that one side becomes grounded and of course you can modify what you see.

Contact arrangements on a relay vary as to the purpose meant for the relay but you can modify that by knowing how everything works.

Contacts can be in parallel or in series or delayed, on or off. One set can operate then the next, again on or off.

N.C is normally closed and N.O. is normally open, but normal is not always when power off, automotive standards are different than industry, different from countries but if that automobile was made by a company that agrees with JIC standards then they build to a standard used in N.A.

Try to be aware of relays in their normal state, that is non energized, is the contact open or closed? With a non energized state that coil has 0 voltage. But when measuring voltage there might be a little, say .5 VDC, but less than 60% of 12 and remember 12 V systems operate at 10-15 VDC.

This may give you a heads up. Trying to get inside the head of an electrical user can be hard, but knowing the facts when all else fails, can allow you to start over, forget what is there and make it right. Often the trick is to know when to stop and when to design and make it your way.

Good luck!

[Pathofinder]

Well I took a few more detailed pictures, it was very difficult to try and peek underneath the fuse box so get the oem factory wire colors going to these pins but the pictures show which terminal they were probing and the tops of the relays in proper orientation for reference if that helps.

(brown relay placed above)


I had some trouble removing the blue relay, as you can tell, its bottom connector is in HORRIBLE condition, looks like someone picked at its clip with a razor blade!! But its probe wire is going to the top left.





The car stalled one me once yesterday, went dead, and I recreated that condition today with the car idling and the fuse box lid off by giving the brown connector a "jiggle" to simulate going over a bump or something, and the car died, so the connection still isnt optimal even in its current ghetto state, I used a small ziptie to hold it tight to the relay beside it so hopefully its trouble free for the time being.

How would you guys go about fixing this problem?? I really need your help here.

Knowing what was originally patched would be nice aswell.

Thanks so much guys!! If more detailed information is needed, I can go ahead and remove the battery and gain better access to the fuse box

[Chuck Tribolet]

It looks like the lower left hole in the blue relay socket is missing the connector, and there's a chunk broken out of the socket.

I gotta do a conference call, I'll dig a little deeper afterward.

[Chuck Tribolet]

If the wire from Bosch #85 (hot side of the coil) goes to the upper left pin of the blue relay, that's Fuel Pump Relay 2, Pin 1, which
is the hot side of the FP2 relay coil, and is hot when the ignition switch is in ON or START. That means the Bosch relay will close
when ever the ignition switch is in ON or START.

With the missing connector at FP2 pin 2 (ground side of the relay, I don't think the FP2 relay is going to close ever.

There MAY be a missing connector on the brown relay, upper left corner. It's hard to tell. Does Bosch #30 go to that connector?
because that would be really strange as that is, according to the FSM, pin1 and always hot. If the Bosch release closed, it would
ground it and blow a fuse. But the picture on top of the brown relay says pin2, which the ECU ground to close the ECM relay. I'm
thinking the brown relay picture is correct, and this band-aid is to get the ECM relay to close when the ignition is on.

I think if you can get reliable connections at the blue and brown relays, you truck will be reasonable reliable.

[Pathofinder]

It looks like the lower left hole in the blue relay socket is missing the connector, and there's a chunk broken out of the socket.
.

Yes youre right the bottom left of the blue relay female connector was damaged so much that it looks like they crimped on that 3" piece of wire you see in the picture to the oem black wire, and the metal connector that grabs the male relay pin was soldered on the end of that wire, so when I pulled the blue relay off that wire stayed connected to the relay and I had to pull it off individually, seems to be a tight connection though.

There MAY be a missing connector on the brown relay, upper left corner. It's hard to tell.

I think if you can get reliable connections at the blue and brown relays, you truck will be reliable.

The top left pin of the brown relay was definitely still there and in good looking condition. Notice how the "grey" relay to the right seems to be cracked ontop? Almost looks to have been hit with something. I wish there was a pathfinder in the junkyard close to me with the 3.5 engine, but I guess that one is still functioning, but Id like to replace it anyways.


I suspect this new info may change what you think is bandaided as that connector is not infact missing so I will wait to hear back from you Chuck.

Again, I greatly appreciate the time youre taking to cross reference my girly lingo back and forth to the FSM, Id be lost without you!!

[Pathofinder]

page 2 already!! darn this forum moves fast. bump me

[ARKQX33V6]

How are you doing with that beast?

[Pathofinder]

Havent touched a thing since my last post, I was hoping chuck would im after my last post since I think it might change some things he thought. The truck has been taken off daily driver duties though for now

[Chuck Tribolet]

OK, the fuel pump will work because they had patched around the broken blue relay connector.

I'm not sure why the band-aid is there, but it certainly seems necessary. There's a bad connection in it somewhere that you need to find. If you have good connections, it should be OK. From something you said earlier, I think it's at the brown relay.

[Pathofinder]

Darn that sucks so Im probably never going to have that oem and working fine again. I dont really get how to "check" the wires at the brown relay other than wheat I checked in that the pin connnections are tight.

Should maybe the wire/connection point that is tapped into on the brown relay just need to be grounded for it to work?? Is that all this relay/patch is doing?

Id just really like to get that relay out of the engine bay, its cheap looking and I hate it for some reason lol

[ARKQX33V6]

It's tough for Chuck or anyone to diagnose wires and relay logic when the previous repair is not logical or is not related back to the repair man as a logical repair. It is a nightmare to fix others fix ups especially on a computer.

As a suggestion go find the same year vehicle and take pictures of the problem area, then you can compare one to the other. You have the repair manual, but the electrical schematics are there but if you are not used to reading them it too is a nightmare. Especially when the drawing refers to other drawings.

My QX4 would be different than your 2 WD Pathy, so my drawings are of no use.

Is there a way to confirm what you have is in a published drawing , I get a copy and then we compare notes.

The obvious problem may very well go deep, it amounts to the work done by somebody before you and I have spent my working life in repairing these messes. Often it is easier to start over from square one, than to figure out someone's mind

[Chuck Tribolet]

First step is to make it reliable. Earlier you said that you had put the wire from the Bosch relay to the wrong pin on the brown relay. I think you have a loose connection there. It needs to be a good crimped or soldered connection.

[Pathofinder]

That would make this relay quite permanent though, Id like to delete it

[Chuck Tribolet]

You could still remove it. Just cut the wires and tape them up.