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does any one know what causes a wait to start light delay

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Wait to start delay is caused by a internal memory errors and having a hard time booting software during key on. So it basically telling you that it ready to fail.

Wait to start delay is caused by a internal memory errors and having a hard time booting software during key on. So it basically telling you that it ready to fail.

"It" being the ECM.
  • Author

thank you all much needed knowledge

I'm unclear as to the Original Question? The Wait to start reads the Engine Temperature. I think it is mainly the IAT (Intake Air Temperature) in the manifold which is water jacketed. So whether the WTS light comes on at all or how long, depends on the IAT. During the WTS cycle the intake grid heaters run, drawing power from the batteries, heating the air in the intake. (This is why starting fluid must never be used without disabling the grid heaters... an explosion will result!) If the block heater is plugged in, the element in the block coolant is warmed & thus the whole engine, raising the IAT reading, shortening the WTS cycle.Now if there is a delay in the Wait To Start engaging than the ECM is failing. So now we've covered both possible ways the question might have been intended.

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the question was for my 99 cummins i would turn on the key and it took about 1.5 minutes before the wait to start light and heaters would come on then it started fine. having both my computers flashed hope it works. thank you guys for your imput.ps this is at 10 degrees out side

Wait to start delay is caused by a internal memory errors and having a hard time booting software during key on. So it basically telling you that it ready to fail.

Mike, by delay you mean for the :wts: light to illuminate or extinguish? I always thought that when it was colder, it took longer due to the heater grid staying on longer than in warm weather and it being linked to the IAT probe like Russ was saying. I R Confused.
  • Owner

the question was for my 99 cummins i would turn on the key and it took about 1.5 minutes before the wait to start light and heaters would come on then it started fine. having both my computers flashed hope it works. thank you guys for your imput.

Ok. Long post coming... What happens is just like you home computer when you turn on the key to your truck. The power is given to all the computers (ECM, PCM, AirBag, Anti-lock, etc.) But staying focused on the ECM when the power is given the computer reads the contents of the EPROM and loads into memory just like you PC does when you turn it on. Once the software is booted up then the software runs as designed. So during this long wait there is memory errors and the system keeps rebooting and rebooting trying to get up and running. So the first thing the software does once booted is check the IAT temp and trip ON the wait to start light. The wait to start light cannot be turned on till software is loaded from the EPROM there is no way around this. So if the on board RAM is failing throwing error it just gets longer and longer. Here is what's inside the ECM case. Processor, RAM EPROM, etc... post-2-138698198101_thumb.jpg This is the connector to the 50 pin connector and decoding the sensor input. post-2-138698198109_thumb.jpg
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what i mean is a delay before is comes on then it stays on awile depending on the temp

OK, now we are clear. My Wait-To-Start comes on almost immediately. A couple of seconds?

  • 4 weeks later...
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got burned on my ecm meaning set it in to have it rebuilt on have not seen or heard about it in over a month.:moon:but i just bought a used one and it solved all of my problems .:thumbup2:

I have been the rebuilt ecm route with the results being a nice pricey paper weight. Had to send it back the first time it was rebuilt. Actually they told me my core was bad and I also lost my core charge. The freshly rebuilt one generated a 606 code that the core did not. I ended up with one from Dodge. Wasted a lot of time and money.

  • 6 years later...
On 3/20/2013 at 9:40 PM, dripley said:

I have been the rebuilt ecm route with the results being a nice pricey paper weight. Had to send it back the first time it was rebuilt. Actually they told me my core was bad and I also lost my core charge. The freshly rebuilt one generated a 606 code that the core did not. I ended up with one from Dodge. Wasted a lot of time and money.


Just recently had to send my ECM back to be repaired again, after only 3 months. Need to find time to check the wiring harness I suppose. But I've had the spare ECM since and no issues at all.

3 hours ago, gipperkid said:


Just recently had to send my ECM back to be repaired again, after only 3 months. Need to find time to check the wiring harness I suppose. But I've had the spare ECM since and no issues at all.

Thats got to make you wonder since the spare is working. When mine went it was hard to find anyone who knew much about them. Found this place during my searches but after the battle.

 

WTS is just the coded way of the ecm telling you that it is booting. 

 

Kinda like this.  Nothing more than a notice that "it's booting"   

 

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