"wait to start" light?

[JHenry]

I am a new member of TDR. I recently sold my '03 Quad Cab to my son and bought a new '06 Quad Cab SWB. When I first took possession of the truck the "wait to start" light came on every time I turned on the key and I could hear the click when it turned off. After the third or fourth day I noticed the light was not coming on and over the last 3 weeks that I have had the truck the light has come on about 5 or 6 times. My dealer (of course) says that is normal but I don't believe it. Has anyone had a similar problem? Thanks for your consideration of my question. Jerry Henry

 

[bpenrod]

What is the outside temperature. Over something like 55 or 60 the heater grid is not used and the wait to start light just comes on and off wotht he system check.

 

[TowRig]

Wierd, I have had my 06 since Aug and have never seen the wait to start light ever.

 

[JVolpe]

My wait to start squiggly comes on every time I turn the key to on regardless of the outside temp. Below 50* will stay on a few seconds longer and will hear/see the lights dim and grid heater on and off cycle for minute or so.

 

[JHenry]

The outside temp right now ranges from 35 to 60 degrees, depending on the time of day. The operation of the light is very erratic and without any pattern. With my '03, the light came on briefly every time I turned the key on. With this truck, it almost never comes on.

 

[JHenry]

As I mentioned, when I first bought my truck, the light came on every time I turned the key on for the first few days. That is how it operated in my '03. Now the light almost never comes on, and it's colder now than 3 weeks ago when I bought the truck.

 

[MacHaggis]

Question is -- Is it coming on as part of the initial test cycle that lights up all the warning lights?

 

[rbattelle]

I recommend reading the owners manual.



The light should come on for a couple seconds when the key is first turned to "RUN". That's the bulb test (and some other things, but I won't confuse you further).



Preheat operation is governed by the following IAT sensor readings (T is temperature):



30F< T <66F = wait to start will illuminate for 10 seconds prior to engine start

15F< T <30F = wait to start will illuminate for 15 seconds prior to engine start

-40F< T <15F = wait to start will illuminate for 30 seconds prior to engine start



You CANNOT assume that the IAT sensor reading will correspond with the outside air temperature.



The only thing that might explain an abnormal wait to start light would be a malfunctioning IAT sensor. This could easily be tested by the dealer.



-Ryan

 

[Dieselnut59]

OR you could just 5H1Tcan the whole thing. On the passenger side battery, there are two fusible link plugs on the positive post. Remove them and tuck them away where you will never see them. I did this when I first bought my '03 and have done it to all my company and personal trucks. On the '98 down trucks, you can pull one activate wire (push on plug) off each solenoid. They are located on the driver side fenderwell on '89-98's. Medium truck and off road equipment 3. 9 and 5. 9 engines do not use pre heat (grid heaters). It is an emission control device. I could see how it does help with starting in very cold climates, but for me, it puts an un necessary drain on the charging and electrical system. Junk it, or at very least, if it is not clod, ignore the light. Cummins engines have plenty of compression to crank without cold start assist.

 

[JHenry]

It comes on when I turn the key on maybe once in 50 or more times.

 

[Papa Delta]

Mine comes on every time....

I turn the key to run. The amount of time it stays on is temperature dependent. If it does not go out after the chime rings which is 5 times, I turn the key to the off position and then back to the run position to recycle the grid heater. This is the recommended starting procedure for cold weather starts per the owners manual. As rbattelle stated, you should give it a read.

 

[JasonBrown]

Mine acts exactly as owner's manual states. Cycles with the dash lamp test when it's above about 45 degrees. It has actually been cold enough to need it a couple of mornings here, but it has only got down to about 40 degrees so far this year. But after it cycles it starts right up.



2005 CTD, quad, 4x4, auto



This is my first diesel and I just love this truck. It is just the coolest truck I have ever had, and I have had all of the big 3 gassers over the years.

 

[DieselFite]

JHenry did you figure out what the problem was with the wait to start indicator? I purchased a 06 on Monday and by Wed. the indicator quit working like yours did, it's 20 degrees outside right now.

 

[JSchutz]

Dieselnut59 is probably right. We don't get temps below about 20 here so I can't answer for the northern crowd but in NC I have started mine with and without waiting for the light and there is no discernable difference. Jeff

 

[JEly]

I have an 06 and I have noticed it will come the first start up and if it is up to temp it will not come again until the trucks sits for a long period of time. My 03 the light came on at every start.



Jim

 

[amsoilman]

Read what Ryan said in POST #8. He is absolutly right! THe light is totaly dependent on intake manifold temperature, as this is where the IAT sensor is located.





Wayne

amsoilman

 

[NavyDood]

The Inlet Air Temperature/Absolute Manifold Pressure sensor is the sensor that is located on the OEM air filter housing. The ECM gets it's info from the sensor then goes through the PCI data bus then o the instrument cluster.



Now, as to why you aren't seeing it on your 06, I don't know. Maybe they changed the way the "wait to start" illuminates. If the grid heaters don't need to cycle, then maybe the light doesn't come on now.



What you see on the overhead console is irrelevant. That reading comes from the ambient temp probe which is located right next to the drivers side headlight. It is not tied into the ECM at all.

 

[RMachida]

Then I'd have to say that the block heater works very well. After being plugged in all night, the wait light only comes on for a second even when it is -20 F.

 

[jwduke]

Agreed, they do work VERY well. Mine started at -16*, without being plugged in.