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Discussion Starter #1
Hi Guys.
Just checking.
Is is the main relay ?
I just took this pic under the dash.

2003 Honda Odyssey Main Relay Photo by coffee-3000 | Photobucket

My car had a hard time starting today.
It would crank . . . but not start.
I would keep trying.
crank . . .
crank . . .
Then it would reluctantly start.

I have some coil issues that I mentioned in another thread.
They might be related to this issue . . . but I'm not sure yet.
I'm going to resolve the coil issues first.
But I just planing for the next steps which might be the main relay.

Thanks again,
Joe
 

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Do you hear the fuel pump run? If main relay issue I think you lose the fuel pump.

Does the green key come on then go out after a couple seconds? Prove the immobilizer is not the issue.

Is it only when it's cold and if so does it rev up a bit when it does start? It should idle up over 1k when first started then slowly drop down. A IAC sticking closed will make for no rev up and hard starts. If it starts right up with a bit of throttle this may be your issue.
 

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Discussion Starter #3
I'm not sure if the pic made it so i pasted again.

It hard to hear if there is any noise from the pump with all the cranking.
The cranking drowns out other noises.

I'll listen harder and check the green key.
But it does start.
Just takes about 10 seconds of cranking.
So the fuel pump is working.
 

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Hi Guys.
Just checking.
Is is the main relay ?
I just took this pic under the dash.

2003 Honda Odyssey Main Relay Photo by coffee-3000 | Photobucket

My car had a hard time starting today.
It would crank . . . but not start.
I would keep trying.
crank . . .
crank . . .
Then it would reluctantly start.

I have some coil issues that I mentioned in another thread.
They might be related to this issue . . . but I'm not sure yet.
I'm going to resolve the coil issues first.
But I just planing for the next steps which might be the main relay.

Thanks again,
Joe
Yeah, that's it. Takes some prying to get it out, too.
 

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Photobucket is the worst service ever. Just upload your pics here as an attachment.
 

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It hard to hear if there is any noise from the pump with all the cranking.
The cranking drowns out other noises.
Turn the ignition key just to ON. You should hear the fuel pump run for two seconds.

If you hear it, you know the relay and the FP are good. If not, it could be the relay or the FP. However, the main relay is more likely to fail than the fuel pump.

Dave
 

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Discussion Starter #8
It is not starting today . . . just cranking.
It was able to start yesterday after the third try.
I'll try again tonight.

I can hear the fuel pump
 

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Your pic IS of the main relay.

It's actually good that your intermittent problem is now constant. That should make it easier to find.

It would help if you observe exactly what the green key light does when you take the key out, and then when you put it in and turn the key to ON (before starting).

Also good to hear that you hear the fuel pump run.

This thread I started, and in particular a post with an annotated circuit diagram may help in the understanding of how the main relay, fuel pump, and immobilizer system all interact.
http://www.odyclub.com/forums/24-1999-2004-odyssey/294105-immobilizer-flakiness-my-99-ex-voltage-related-2.html#post1792233

Even with the service manual, there are some things that are not exactly specified, which I discovered through experimentation there and reported in that thread. BTW, for me, no real repair was ever done, and the car has been running flawlessly for many months now. My problem (that was confirmed to be a immobilizer issue) just went away.

Other suspects to keep in mind: ignition switch, fuses (as shown on the circuit diagram)
 

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Discussion Starter #10
Thanks Olkskewel. I'll read your post/research tonight.

My car just started after after an extended cranking period. . . maybe 10 seconds.
So can I rule out the fuel pump since it is pumping well now ?
 

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Thanks Olkskewel. I'll read your post/research tonight.

My car just started after after an extended cranking period. . . maybe 10 seconds.
So can I rule out the fuel pump since it is pumping well now ?
In my opinion you can almost rule out the fuel pump just because it is a Honda Odyssey. Really, I don't think these fuel pumps ever go bad. People might replace them, but not necessarily because the pump failed. I've got a brand new one in my garage that I bought because I mistakenly believed I needed to buy the full assembly just to get the fuel level sender (float thing attached to the pump). Not even really trying to sell it because I know nobody will probably really need it. But hey, if anyone wants to send me an offer ...

I'd focus on the green key light, quickly check all those fuses, and then possibly the main relay. (I'd rank all those above an actual fuel pump failure of any sort)

If it's back to intermittent, there may be a chance of a flaky connection in the relay. If you have a soldering iron, it is very easy to pop the relay out, visually inspect the solder joints and re-flow as needed. And if you've got a few electrical tools and convenient 12V power source (I use a cordless power tool battery for this), you can do a very careful bench test of the main relay to convince yourself it is rock solid ... or not. That's what I did.
 

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When my girlfriend's Accord had its first engine startup problem, I went with the odds and just replaced the main relay. The engine started first time, every time after that.

The main relay is inexpensive to buy and easy to install. It's much less hassle than running out on even one rescue/repair mission.

I'm not saying that the main relay is always the problem, but it is a common point of failure on Honda's. If it had not fixed the problem on the Accord, at least I would have known what it wasn't. (BTW, bought the OEM part.)

Dave
 

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It is not starting today . . . just cranking.
It was able to start yesterday after the third try.
I'll try again tonight.

I can hear the fuel pump
Did you try starting it with the accelerator pushed down a bit like I mentioned? It has been very humid and rainy in the Northeast lately, more air into the engine may help especially if the IAC is sticking. It's an easy thing to try when it doesn't start or is slow to start.
 

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Discussion Starter #14
Thank you all for your comments.

oldskewel: Great post on the immobilizer. It looks like if the computer doesn't "think" you have the correct key . . . or a damaged key . . . it will shut down the fuel system so the car won't start. It will crank . . . but not start. And if you have another key nearby with a chip in it . .. it can get confused and enable the immobilizer. I'll keep a close eye on the green light.

OdyinNH: While it's been cranking . . . I've been pushing the accelerator.

davesdrivesody: Thanks for the tip. I'll get a new main relay. For what I've read on this site, it seems like just a normal part of maintanence with Odysseys. Even if it doesn't solve this issue . . . I'm sure it will prevent a future issue. Is there a screw holding the assembly ? Or do I just wiggle the little black box off it's bracket ? I'll get a new one rather than solder the existing one since I don't have a soldering gun
 

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In order of above:
-Another key should not confuse the immobilizer, all it cares is that there is a good key. Watch the green key dash light and make sure it reacts as it should when the issue arises but I'm doubtful of that for the issue because you say it sometimes starts after a few cranks. Unless of course you turn the key all the way back before trying again.

-Ok, 1/3 to halfway is plenty of pedal but sounds like this is not helping.

-The relay just wiggles out but it is in there solidly.

Curious, when you say it started reluctantly, can you describe that? As in sounds like it starts like it was flooded or something else?
 

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Discussion Starter #16
.

Curious, when you say it started reluctantly, can you describe that? As in sounds like it starts like it was flooded or something else?
Hi OdyinNH. That's a good description. It actually sounds like it flooded . . . like it's choking. Then it gets just the right amount of air and then turns over. But I think this sound is the same sound for the opposite. That is . . . when it is starved of gas. So I guess a better description is that is
"choking".
 

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Is there a screw holding the assembly?
You have three choices to remove the relay:

1. Wiggle it off the bracket. It's a very tight fit, like OdyinNH mentioned above. Also it has a one-way wedge tab molded into the case that secures it to the bracket. You have to override the tab so it will slide off the bracket. Look at the new one and you will see what I mean.
2. Remove the single bolt that attaches the relay and its bracket to the van then remove the assembly. Requires a bit more dexterity, but it's easier to swap the relay on your bench than under the dash.
3. Leave the relay housing in place and slide the workings out of it. You just need to pry the two long sides of the housing outward a bit to clear the locking tabs. Again, have a look at the new one and you will see what I mean.

I used #2. I found #3 after; I would give that a try next time.

Dave
 

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Now that Dave mentions it, I think I did #3 too. Mine looked perfect inside.

As for the starting, I wonder if the car is flooding, leaky injector or something. Next time it won't start put the pedal to the floor which opens the air path completely and limits/stops fuel flow.
 

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Discussion Starter #20
You have three choices to remove the relay:

1. Wiggle it off the bracket. It's a very tight fit, like OdyinNH mentioned above. Also it has a one-way wedge tab molded into the case that secures it to the bracket. You have to override the tab so it will slide off the bracket. Look at the new one and you will see what I mean.

Dave
Thank you Dave. I removed it using option #1.
I've include the picture here.
It looks pretty beat up.
I got a new one from Honda and replaced it today.
But bad news . . . . I'm still have the starting issues.
It seems to be marginally better . . . but it is still struggle to start.
main-relay-4.jpg

I'm going to try to clean the IAC.
Can you tell me how to remove it ?
I see the two rusty Philips head screws holding the electrical connector.
Do I remove these ?
And . . . are there Philips head screws that I have to access from underneath ?
What is the best way to get at them ?
He is a pic of what I'm seeing.
IAC-2.jpg
 
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