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The wait to start light comes on and does it thing as usual when its above freezing.

Truck starts normal and works great.

If its colder than freezing, it will take a few extra seconds to light the light.

It also takes longer for it to go off when its colder, I think this part is normal.

Of course when its hot out the light is on and off right away.

Do I have an issue with the ECM or am I just crazy (normal) 

No codes when scanned.

I am not using it for a daily driver ...too darn cold.

When the roads are nasty I will drive it cause It will get me there.

Thanks

Chris

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  • Author

Next time the wife and I go for coffee with it I will make note of temps and time it takes to do its thing. 

I thought it was normal until I read about other folks troubles with the delay in it lighting up.

Thanks

Chris

  • Author

Thats correct when warm.. lets say 70 degrees, the light is on and off right away.

However when cooler. lets say 35 degrees the light is on right away and stays lit untill the grid heaters do their job.

When it real cold out ( well real cold for us) the light does not come on for maybe 10 or 15 seconds .

Then it lights and the grid heaters do their thing. I do understand that the colder it it the longer they stay on.

The pause when real cold is what makes me ask questions. 

Thanks

Chris

The pause before the light comes on has me a bit concerned. I would start searching for an ECM as yours is not booting as fast as it should.

Your :wts:  is acting totally normal. When it takes longer to go off you can see the volt meter get pulled down to about the 10 volt range. Soon as the light goes off the volt meter goes back to normal. That is the grid heaters running to assist in the starting.

  • Author

the light does not come on for maybe 10 or 15 seconds.

  read my above post.

This is the the part that is the ?

Chris

Sorry I guess I mis read what you meant. If hte light is not coming on as fast as it should then it NORMALLY means the ECM is taking longer to start up than it should. You could be looking at anything from A loose connection to an ECM failure.

  • Author

Loose connection...that right there is probably a great start.

That would explain it working most of the time until its really cold.

I think so anyway. Is it possible that when its colder that a wire contracts just enough for the ECM to loose a connection ...

Thanks Tom...this gives me a place to start.

Chris

what is the 'factor' for running a grid heater 'x' amount of time? Is there an internal temp probe that tells the ecm 'its hot enough inside the plenum'..

or is there a simple curve within the ecm that takes iat and computes the amount of on-time for the grids?

edit, just the other day, I was priming the fuel system after a filter change, and noticed the grids were 'squealing'. Suppose this was frost burning off the grids?

Edited by rancherman

The ECM looks at what resistance the IAT is at and has a set time for a set resistance.

I would also check the IAT connector and clean it. Could be dirty and when cold not connect as good.

  • Owner

The ECM looks at what resistance the IAT is at and has a set time for a set resistance.

 

Yeah but if the software never boots up in the ECM then there is no :wts: till the software is booted up. The first few instructions is to check IAT temp and figure out how long to run the grid heater.

  • Author

Well...a new development this evening.

My Jetta the daily driver had a frozen drivers window...

I was a bit to agressive and managed to screw up the track and now the window is out of service.

SOOOO   I cleaned the snow off the trusty Dodge and put the key in...I was a bit skeered of the wait to start light.

Wouldn't you know it, the little bugger lit right up as soon as I turned the key. 

And its cold and has been cold here...10 F right now and was 5 below last night.

It dosen't get much colder than that around here...even though you folks think we make the cold air...ha ha.

The batteries might be a little low because I have not used it much this winter.

It fired right off when I rolled it after the light went off.

I must say that impressed me quite a bit...2 thumbs up for the Dodge 

Regards Chris

  • Owner

Good ol' Yankneck696 usually suggest to go over all the connectors with dielectric grease and then cycle each one 3 time to clean the contacts and also work the grease into them.

  • Author

When I started this morning the light was slow to come on...it did come on and started fine and there was no window malfunction.

Might have been a wardrobe malfunction but that's a whole nother story.

Chris  

  • Author

Planning on doing the electrical connection cleanup and dielectric grease job...today or maybe tommorow.

Much warmer temps tommorow.

Is it recomended to unhook both batteries when servicing these connectors.

I would think so and I looked for a post Yankneck made about it but no luck.

Regards Chris

Unhooking the batteries is not a bad thing. If you do then you could clean any connection anywhere and not wory about shorting anything.

  • Author

I pulled the batteries and put them on a maintainer/charger for the night.

I was a tiny bit nervous of moving the fuel filter canister, however when you remove the 2 bolts it easily tips down out of the way.

I removed the allen screw holding connection to the ECM...well what do you know, it was not very tight.

I would say it was finger tight at best.

I cleaned it and put a bit of the dielectric greas on it and re assemebled it working it back and forth a bit to make a good connection.

While I was at it I cleaned and greased the connections the connections on the computer on the firewall.

Re installed the batteries and .....then.

Success, the wait to start lights up right now every time the key is cycled.

My feeling is that the somewhat loose connection on the ECM was my problem.

It has been this way since I got the truck...I should have done this long ago.

i also checked out the alternator for AC noise and if my fancy pants snapon meter is any good I have .001 to .01 ac volts.

I should note that this meter has made me look bad on oacasion on some jobs at work.

I just don't trust it.

Will check again with a fluke meter at work.

Regards Chris

Congrats, Chris! It makes a guy feel good when he can fix things like this!! Good going.