Fuse Block replacement 2004 Vue V6 AWD [Archive]

bluecollarpilot

07-15-2009, 12:04 PM

I've replaced my fuse block under the hood of my 2004 Saturn Vue AWD V6. The car will not start and gives me an engine light and car with a wrench, on the cluster. I am not able to access the ODB II codes.

I don't know what the meaning of the car with the wrench on the cluster is (no owners manual).

The reason I replaced the fuse block was because a short was identified with a volt meter. The car would start only if I jumped the relay for the ignition.

If any other information is needed let me know but I would greatly appreciate assistance with this problem. I am very new to working on this vehicle.

Thank you,

John

YourMainParadox

07-15-2009, 12:16 PM

I had something similar happen. I finally figured out that one of the bolts was not completly tightened and when it isn't randomly certain things would not work... like starting.. winshield wipers and or the delay on them... turn signals...it was very random and tightening everything up fixed it all. Double check everything on the bottom of the fuse panel is snug and tighten the bolts holding it down. Hopefully that might help?

dbywaters

07-15-2009, 12:26 PM

Go back and check connections. The three bolts in the center of fuse block pull the connectors up into the fuse block.
another thing, make sure you have two large wires connected to the terminal on the dash side of the block, it is a chance that one could have been forgotten. There are at least two large connectors that connect to the under side of the fuse block near the firewall side, I think they are green. Make sure they are connected into the bottom of the block.
Do you have all the fuses in the correct places, are they all good...

What does work? does the headlights turn on, does it crank,

I'm just listing things that I would check....since I just did something similar.

bluecollarpilot

07-15-2009, 01:06 PM

far2grumpy

07-15-2009, 01:38 PM

The car cranks over, but no ignition.

the headlights work, windows, wipers.

Fuel gauge does not, abs, not sure what else.

It is a brand new fuse block, specifically for this model. I'm assuming all fuses are good.

What does the car with the wrench mean on the cluster?

Any additional help would be appreciated.

See attached for description of wrench in car ... not much help for you at this point.

Are you sure its no ignition and not lack of fuel?

A security problem will disable the injectors.

I'll try to find ignition schematics.

bluecollarpilot

07-15-2009, 01:45 PM

I stuck the old fuse box back into the vehicle and here is the ODB II code I pulled.

P0685--ECM/PCM power relay control circuit/open

In addition, the only way I can get the vehicle to start is if I jump the ignition relay. Further clarification, it's called ENG MAIN L4, on the fuse box, under the hood.

If someone could pass along a schematic for the fuse block, that would really help.

Maybe this will allow someone to give me an idea.

far2grumpy

07-15-2009, 01:48 PM

See attached for description of wrench in car ... not much help for you at this point.

Are you sure its no ignition and not lack of fuel?

A security problem will disable the injectors.

I'll try to find ignition schematics.

See attached schematic for 3.5 ignition circuits.

bluecollarpilot

07-15-2009, 01:53 PM

far2grumpy

07-15-2009, 02:07 PM

P0685--ECM/PCM power relay control circuit/open

In addition, the only way I can get the vehicle to start is if I jump the ignition relay. Further clarification, it's called ENG MAIN L4, on the fuse box, under the hood.

If someone could pass along a power distribution schematic for the fuse block, that would really help.

I've not found an overall power distribution schematic for fuse block.

I've attached two other schematics related to ignition and starting.

bluecollarpilot

07-15-2009, 02:18 PM

The information you are giving me is very, very good.

I see a lot of references to "Power Distribution Schematics in Wiring System", not sure what that means but I'm guessing there is more schematics according to the reference numbers.

Couple more questions:

Where is the PCM located?

Are there more fuse blocks than the one under the hood and on the passenger lower left?

I have jumped the relay for ENG MAIN L4 number 85 to 87, once I do that i am able to start the car and everything behaves normally.

Thanks much!!!

far2grumpy

07-15-2009, 02:20 PM

bluecollarpilot ... have attached another diagram with additional power distribution info.

There are two BCM fuses in center console which could affect start ... you didn't mess with but who knows the evil that lurks in the Vue's heart?:hmpf:

bluecollarpilot

07-15-2009, 02:23 PM

LOL, thanks.

How do I get to those two fuses? They are definitely worth checking out.

bluecollarpilot

07-15-2009, 02:35 PM

I didn't realize you were talking about the two fuses on the passenger side center console, sorry. I double checked those two fuses, they are ok.

bluecollarpilot

07-15-2009, 02:44 PM

I'm starting to think it's not the fuse block at all, but maybe a bad wire or corroded wire. This really sucks...

3RedLines

07-15-2009, 03:39 PM

My 2 cents, maybe all its worth. The relay you refer to has its coil grounded by the PCM.

Here's a snip from the manual on the DTC
This diagnostic detects an inoperative relay. The ignition relay, or main Relay, is controlled by the powertrain control module (PCM). The PCM provides a ground for the relays coil anytime the ignition switch is ON. The MAIN relay supplies ignition positive voltage to many engine control systems and components. The following components receive power from the relay:

The ignition coils
The heated oxygen sensors (HO2S)
The evaporative emission (EVAP) control system solenoids
The camshaft and crankshaft position sensors
The powertrain control module (PCM)

And a pretty picture too:

bluecollarpilot

07-15-2009, 04:01 PM

yes, it seems like something wrong with the power supply or ground for the main relay (86 and 30 of the relay)...so far just a hunch. Where is the PCM? How do I check to see if it is grounding the relay correctly?

Since I can make everything work if I connect 87 to 85 it has to be something with 86 and 30 of the relay. And since I replaced the fuse box, probably the most expensive part, I know it's not that.

Maybe I should focus on the PCM. But I need to know where it is...

Thanks.

3RedLines

07-15-2009, 04:14 PM

The PCM is behind the air cleaner, between the engine and the frame rail. You can probe 86 and 30 with a test light. One side should light up the light, and the other would light up the light if you hook the test light ground to 12v and probe the terminal with ign on. it would light when the PCM grounds that terminal.

Are you sure you got the correct replacement fusebox?

bluecollarpilot

07-15-2009, 07:34 PM

The dealer said I have one of two choices. One for a v6 and one for a 4 cyl. I thought the choice was clear and the fuse block looks identical. I'll check it out and reply with what I find.

bluecollarpilot

07-16-2009, 05:56 PM

3RedLines

07-16-2009, 06:27 PM

check from #86 in the fuseblock (relay coil ground terminal) to pin 54(Brown wire) on the 56 pin connector on the PCM. I think it's the smaller of the two connectors on the PCM, the other connector has 72 pins. See attached pic for an end view of the 56 pin connector. If you're brave you can just ground pin 54 and listen for the relay to click.

I think if that's ok you may be looking at a bad PCM

3RedLines

07-16-2009, 06:38 PM

Also check pin 70 (white wire)on the large PCM connector for 12v, this comes through the powertrain fuse when the key is in run/start.

far2grumpy

07-16-2009, 09:54 PM

I've tested 86 and 30 of the ENG MAIN L4 relay.

30 is normal with 12 volts
86 is not working correctly, with the ignition there is no ground and there should be.

So, I'll focus on the ground wire coming from the PCM, and the PCM itself.

Any other suggestions?

bluecollarpilot ... You're closing in on a solution with great assistance from
3RedLines. Best I can offer is an extract to troubleshoot the main relay circuit ... you are probably well beyond this.

Get in touch if you'd like any of the referenced docs.

bluecollarpilot

07-21-2009, 11:16 AM

Where is number 86 in the fuse block? they are labeled on the back of the fuse block as 1-12 vertically, and a-f horizontally. And there are three banks of wires on the back of the fuse block.

I would like to isolate the fuse block from the system and just check the continuity of the wires.

I grounded #54 on the 56 wire connector and I could hear the relay click over. So that must mean the wiring from the PCM #54 to #86 on the relay must be good...

I tested #70 on the 72 wire connector and did not get any voltage indication when the ignition was in the start/crank position.

check from #86 in the fuseblock (relay coil ground terminal) to pin 54(Brown wire) on the 56 pin connector on the PCM. I think it's the smaller of the two connectors on the PCM, the other connector has 72 pins. See attached pic for an end view of the 56 pin connector. If you're brave you can just ground pin 54 and listen for the relay to click.

I think if that's ok you may be looking at a bad PCM

bluecollarpilot

07-21-2009, 11:35 AM

I have eliminated any question about the fuse block, at least the ground of ENG MAIN relay.

I've tested continuity from #54 of PCM to #86 of fuse block and all checks good.

I do not get power to #70 of PCM during run/start postion.

What does that mean? Where does #70 of the 72 pin connector get its power?

Also check pin 70 (white wire)on the large PCM connector for 12v, this comes through the powertrain fuse when the key is in run/start.

3RedLines

07-21-2009, 01:16 PM

My mistake... I should have said pin 71 red wire. It comes through the PWR TRAIN 10a fuse. When the PCM gets 12 here one of the things it does is ground the main relay control (The brown wire you confirmed good)
Pin 70 is 12v from the main relay when it closes.
Sorry for the mix-up:dizzy:

bluecollarpilot

07-21-2009, 01:42 PM

3RedLines

07-21-2009, 02:58 PM

So, what that says to me is the relay is not grounded through the PCM like it should be but is getting the appropriate 12v signal from #71 in the PCM.

Is that correct? Is it a bad PCM, possibly?

If what the manual says is true: "The PCM provides a ground for the relays coil anytime the ignition switch is ON." then it looks like you probably have a bad PCM

far2grumpy

07-21-2009, 04:34 PM

#70 has 12v when #54 grounds the relay closed #71 has 12v when the ignition is in run/start

So, what that says to me is the relay is not grounded through the PCM like it should be but is getting the appropriate 12v signal from #71 in the PCM.

Is that correct? Is it a bad PCM, possibly?

bluecollarpilot ... I've attached a copy of Main Relay schematic ... I also added likely identifiers for each relay contact (85, 86, 87 and 30).

Help me understand where you are ... referring to diagram ... are you saying once you turn key to RUN/START to apply +12 to PCM pin 71 the PCM does not send a ground from pin 54 to MAIN RELAY pin 86?

However, if you manually apply a ground to pin 54 ... same point electrically as MAIN RELAY 86 ... the relay latches and engine will run?

The desired result of latching MAIN RELAY is to return +12 to PCM pin 70. The relay also powers EMISS 10A Fuse and INJECTORS 10A Fuse.

If you have +12 at PCM pin 70 after grounding pin 54 -- this indicates relay, fuse and wiring is probably OK.

The PCM might not be OK, assuming all other required connections are valid
(72, 73, 52, 51, etc).

bluecollarpilot

07-21-2009, 04:45 PM

Far2grumpy,

What you described is exactly what I have discovered. I would agree in that the PCM is probably at fault, unless there are more tests to run that would rule it out...maybe????

I thought about buying a pcm from a salvage yard, but I don't have a means to program it. Otherwise, it is a $650 part from the dealer. Then the installation and programming fees.

Any other suggestions?

bluecollarpilot ... I've attached a copy of Main Relay schematic ... I also added likely identifiers for each relay contact (85, 86, 87 and 30).

Help me understand where you are ... referring to diagram ... are you saying once you turn key to RUN/START to apply +12 to PCM pin 71 the PCM does not send a ground from pin 54 to MAIN RELAY pin 86?

However, if you manually apply a ground to pin 54 ... same point electrically as MAIN RELAY 86 ... the relay latches and engine will run?

The desired result of latching MAIN RELAY is to return +12 to PCM pin 70. The relay also powers EMISS 10A Fuse and INJECTORS 10A Fuse.

If you have +12 at PCM pin 70 after grounding pin 54 -- this indicates relay, fuse and wiring is probably OK.

The PCM might not be OK, assuming all other required connections are valid
(72, 73, 52, 51, etc).

far2grumpy

07-21-2009, 05:49 PM

So, with key OFF you have +12 at PCM pin 72?

And with key at RUN you have +12 on 70, 71 and 72?

far2grumpy

07-21-2009, 06:02 PM

Another item which has me confused is in post #16 you mention if you jumper MAIN RELAY 87 to 85 "everything works OK".

Check the diagram I attached to two posts back and you'll note there should be continuity between 87 and 85. If a jumper makes the vehicle work it would be because the one that should be there is missing / broken.

bluecollarpilot

07-21-2009, 06:21 PM

So, with key OFF you have +12 at PCM pin 72?

And with key at RUN you have +12 on 70, 71 and 72?

This is correct.

To answer your other question:

I may have mis-spoke when I said that.

Correctly said, when I jump 87 (12v source) to 30, then everything works correctly.

With the ignition on i have 12v at pin 87 and 85. 30 is waiting for the 12v to power the injectors, etc. and 86 is the ground.

So, with key OFF you have +12 at PCM pin 72?

And with key at RUN you have +12 on 70, 71 and 72?

Another item which has me confused is in post #16 you mention if you jumper MAIN RELAY 87 to 85 "everything works OK".

Check the diagram I attached to two posts back and you'll note there should be continuity between 87 and 85. If a jumper makes the vehicle work it would be because the one that should be there is missing / broken.

3RedLines

07-21-2009, 06:22 PM

So, with key OFF you have +12 at PCM pin 72?

Good point F2G! I had assumed that voltage would be there when it possibly may not be

far2grumpy

07-21-2009, 06:38 PM

So, with key OFF you have +12 at PCM pin 72?

And with key at RUN you have +12 on 70, 71 and 72?

This is correct.

To answer your other question:

I may have mis-spoke when I said that.

Correctly said, when I jump 87 (12v source) to 30, then everything works correctly.

With the ignition on i have 12v at pin 87 and 85. 30 is waiting for the 12v to power the injectors, etc. and 86 is the ground.

OK ... do you have a somewhat precise multimeter? If so, connect meter - using ohms scale - to PCM pin 54. Turn key to RUN and check for continuity, or some resistance value, to ground.

If the meter does not deflect - or acts strange - select DC volts and measure level.

far2grumpy

07-21-2009, 06:56 PM

BCP ... I know you have your stuff together, but just thought I should add you can pull the MAIN RELAY and insert one lead of multimeter in socket for relay pin 86 -- this should be same electrical point as PCM - 54.

Of course, if you get nada, you probably need to go direct to PCM.

The purpose of this exercise is to confirm the PCM does or does not output a ground to the MAIN RELAY when conditions are set.

Relays of this type typically have 75 ohm coils, so with a +12 supply the pin 54 output should only have to sink around 160 milliamp. I'm not sure how this output could be "fried", but if it is, we may be able to come up with a workaround.

bluecollarpilot

07-21-2009, 07:02 PM

Ok, I'm not an expert on electricity and testing ohms but here is what I found.
I hope I did it right.

Pin 54 has -.620 ohms and also has 12v output on the multimeter.

Also, the output is steady.

OK ... do you have a somewhat precise multimeter? If so, connect meter - using ohms scale - to PCM pin 54. Turn key to RUN and check for continuity, or some resistance value, to ground.

If the meter does not deflect - or acts strange - select DC volts and measure level.

far2grumpy

07-21-2009, 07:35 PM

If the key was placed to RUN, and meter indicated +12 between pin 54 and ground, it appears either the PCM is flaky or there's some other parameter not being satisfied.

Did you by chance monitor the meter while the ignition was cycled between OFF and RUN?

Would be interested if there were differences with key ON and OFF.

3RedLines

07-21-2009, 08:49 PM

I grounded #54 on the 56 wire connector and I could hear the relay click over. So that must mean the wiring from the PCM #54 to #86 on the relay must be good...

This should have confirmed the relay circuit is working properly. The problem is the PCM is not grounding pin 54 when pin 71 goes 12v (assuming pin 72 also has 12v)

far2grumpy

07-21-2009, 09:18 PM

This should have confirmed the relay circuit is working properly. The problem is the PCM is not grounding pin 54 when pin 71 goes 12v (assuming pin 72 also has 12v)

I completely agree ... I was trying to see if there's anything left of the grounding circuit in the PCM (providing output to pin 54) ... his meter indicated less than one ohm but also +12 volts.

So I asked if he could keep meter on pin 54 and cycle ignition from OFF to RUN to check for differences.

BCP ... if you read this before testing the BCM ... also please remove the relay to make sure its not source of +12 you're reading at pin 54.

far2grumpy

07-21-2009, 10:35 PM

I just completed a few measurements on my 05 Vue 3.5.

With relay out of socket I measured 12.8 volts for pins 85 and 87 ... this would be B+ (battery - un-switched).

Pin 30 measured 5.68 Kohms.

I couldn't take a resistance reading for pin 86 because of DC voltage ... I tried to measure the voltage and found I was looking into a capacitive network (this would be inside PCM - pin 54). The meter peaked at 120 millivolt and slowly reduced to a stable 3.5 milllivolt.

BCP ... perhaps you could do same test ... remove MAIN RELAY and check for ohms on pin 86 ... if meter indicate voltage ... select DC volts scale and with positive lead on 86 put the negative lead on ground (or battery ground post).

See if your PCM pin 54 has approximately same values as mine.

bluecollarpilot

07-24-2009, 12:37 AM

Ok, guys...

I took it to the dealer, told them what I found and the after-market warranty that I purchased with the vehicle will fully cover a new PCU, which is really kick butt.

The dealer even covered my $50 deductible because of the info I told them...all thanks to your help. Completely invaluable!!

Thanks for all your help.