Any codes? Usually only things I see are the relay on the passenger battery box. The heater itself or a cluster. Check codes. If none get a test light and check across the relay and if good check at the heater itself

 

What's the temp outside?

 

Thanks for response guys, I didn't have much time to mess with it today and my volt meter is broken so all I have is a test light. I had the wife turn the key to the on position while I had my hand on the relay by the PS battery and it didn't click or anything. I put the test light on the terminals on the grid heater and it showed no voltage. I guess I need to test the wire leads at the relay tomorrow and see if I get anything. I have another instrument cluster and I installed it and I still don't get a WTS light so I dont think its in the cluster. I also checked for codes with my cheap advanced auto scanner and I got no codes.

 

Put test light on left side of relay looking down at it from passenger fender. Should have constant power. So if it's cold enough out and it wants the grid heater on and you have no power going to the right side of relay when key on. then replace it.

 

So where do the two small wires go on the relay? Is one a trigger wire and the other goes to the WTS light?

 

One is the trigger wire ("Intake Air Heater Relay Control" signal) coming from ECM.
The other (Black color) goes to ground.
The relay coil would be energized when both control signal and ground were present at the same time.
It's the ECM controlling the WTS light on/off when it's required.
And light ON didn't always meant the grid heater was ON.
ECM would turn ON the WTS light (with chimes) when it saw a fuel delivery issue.wink2:

 

I have an 06 also and unless it's fairly cold out mine never comes on

 

Most likely what's going on. Usually if there is an issue the light stays on constant or sets a check engine light

 

the grid heater kicks on when its 66* or below

 

I do think the light should come on then off when light bulb testing the cluster when key on.

 

Alright, I have power to the left side of the relay and I have a good ground on the small black wire. The small wire with the yellow tracer is not getting power when I turn the key on or when starting or in run mode. What controls the trigger power to the relay? Is there a fuse? I looked for fuse but couldn't find one.

 

I have a good ground on the small black wire. The small wire with the yellow tracer is not getting power when I turn the key on or when starting or in run mode. What controls the trigger power to the relay? Is there a fuse? I looked for fuse but couldn't find one.

As I said before the ECM would send the control signal (12V) to energize the coil whenever it thinks its needed.
It would only be needed to turn on the grid heater when the intake air temp was below 66F.

The grid heater operation had NO direct electrical connection with the WTS light.

The grid heater operation and WTS light were controlled by the ECM separately.
Of course ECM would turn on the WTS light when the grid heater was on.

You are having a "WTS failed to come on once at key on" issue and you are not having a grid heater issue.
So you are barking around the wrong tree.

 

So I just put a hot jumper wire from the + battery post the the small post on the relay where the black with yellow wire goes and the relay works and I get power to the side going to the heater grid, so I am not getting power from the trigger wire. Any suggestions?

 

That proved that your relay was GOOD.

 

I was just thinking of putting the jump wire to the trigger wire to see if the WTS light comes on but was thinking that may be a low voltage circuit and I don"t want to fry anything.

 

The WTS light was on the cluster.
I don't think there was a trigger wire for you to jump.:wink2:

 

Well either way the WTS light should come on when the key is turned on to test and make sure its working, I am getting no light during test mode.

here is the operation of the grid heater via Dealerconnect.


OPERATION
The wait-to-start indicator gives an indication to the vehicle operator when the air temperature within the diesel engine intake manifold is too cool for efficient and reliable engine starting, and that the intake air heater grids are energized in their pre-heat operating mode. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Engine Control Module (ECM) over the Programmable Communications Interface (PCI) data bus.

The wait-to-start indicator Light Emitting Diode (LED) is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED will always be off when the ignition switch is in any position except On or Start. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor. The instrument cluster will turn on the wait-to-start indicator for the following reasons:

Wait-To-Start Lamp-On Message - Each time the cluster receives a wait-to-start lamp-on message from the ECM indicating that the air temperature within the intake manifold is too cool for efficient and reliable engine starting, the wait-to-start indicator will be illuminated. The indicator remains illuminated until the cluster receives a wait-to-start lamp-off message, until the ECM detects that the engine is running or until the ignition switch is turned to the Off position, whichever occurs first.
Actuator Test - Each time the cluster is put through the actuator test, the wait-to-start indicator will be turned on, then off again during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.
The ECM continually monitors the engine intake air temperature sensor to determine when the intake air heater grids should be energized in their pre-heat operating mode. The ECM then sends the proper wait-to-start lamp-on and lamp-off messages to the instrument cluster. For further diagnosis of the wait-to-start indicator or the instrument cluster circuitry that controls the indicator, (Refer to 8 - ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING).

For proper diagnosis of the engine intake air temperature sensor, the intake air heater grid control circuits, the ECM, the PCI data bus, or the electronic message inputs to the instrument cluster that control the wait-to-start indicator, a diagnostic scan tool is required. Refer to the appropriate diagnostic information.
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Well either way the WTS light should come on when the key is turned on to test and make sure its working, I am getting no light during test mode.

Actuator Test - Each time the cluster is put through the actuator test, the wait-to-start indicator will be turned on, then off again during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

Key ON was not the way to start the "Actuator Test".

I didn't recall exactly how to start that, something like key on/off/on.

And I am not sure mine come on when key on since I never have had any issue with it.
I can check it when it get home later today.

 

Hold down the trip button on the cluster as you turn the key to the on position.

Try this.
It may be start the "Actuator Test".

 

I did that and the WTS light showed

 

So tell me if this would work to test, ice down the IAT sensor and see if the system works.

 

So let me tell you why I started chasing after the WTS light. I had a remote starter installed last week and the crank cycle is timed and I do not believe tied into the WTS timer which I would like to get corrected. I do know the engine will shut down when revved to 2500 rpms. So that tells me it is reading a tach signal. I have experienced remote starters in cold weather before and they need to tell the starter to start when the WTS light goes off not 10-15 seconds after it goes off, and then shut the started off when a specific RPM is seen, not a set 10-15 second crank time. So where would the remote starter tie into to read the WTS signal? Anyway since were talking about the heater grid would it be possible to test the system by cooling down the IAT sensor?

 

There were Preheat Schedule and Postheat Schedule.
Preheat depends on MAP intake air temp.
Postheat depends on IAT inlet air temp.
I think Preheat happened before engine start.
So I think you can try by cooling down MAP sensor and then key on to see if the WTS light come on.
It might not work if the coolant temp was not low enough.

You can use the grid heater relay control signal to tell "when" the ECM switched on/off the heater.

If you plug in your block heater there would be no preheat operation.

 

Sorry Pwong I missed your post, My truck has a K&N air intake with I guess the MAP sensor mounted on part of the K&N air intake with a little air filter on it, you think I need to cool that down and try first? I was thinking that the original air box had both a MAP sensor and a separate IAT sensor on it, not sure though. I guess I could drive it to heat up the coolant then try to drop sensors in a cup of ice, just need to figure out which sensor controls it in the preheat mode, correct? What is the sensor I see on the intake manifold plate just behind the grid heater?

 

I was curious so I just went out and checked my truck. The WTS light does NOT come on with normal key on. It did come on with the Actuator test. Temperature here is about 87 degrees right now.

My WTS does work normally when it is cold enough.

 

My WTS hasnt turned on in months. Literally. It works though. I used it ONE time before.

 

So I'm going to try to test the system by dropping the temp on the IAT. Is the sensor right behind the intake horn on the intake plate held down by a couple of torque or allen head screws?

 

No. Its the one on the air filter assembly.

 

But on the stock intake system on an 06 5.9 cummins is the MAP sensor and IAT sensor two separate sensors?

 

IAT is on the manifold, it is a dual function sensor with the MAP. AIT is on the TQ tube at the air filter housing.

 

It's the inlet air before the turbo and intake air after the turbo.
After the turbo was the manifold.
There were dual pressure/temp sensor, one before the turbo and one after the turbo.
Preheat depends on the one (MAP) after the turbo.

Don't know what coolant temp would stop the grid heater operation.
Just how plugged in the block heater would stop the heater operation.
Keep that in mind while trying to play with the manifold air temp on the MAP sensor.

You need a COLD engine to try.

 

Preheat happens when key on engine off, depends on the sensor after the turbo, intake air.
Postheat happens when key on engine running, depends on the sensor before the turbo, inlet air.
Engine has to be COLD.

Hopefully it's clear now. Lol.

 

So I would cool the sensor on the intake to try and get WTS and the heater grid to come on, correct?
The post heat tells the grid heater to stay on after it starts, and is controlled by the preturbo sensor. Is that correct?

 

Or just take advantage of the cr injection and start down to like 55 without the heater.

I feel like this has gotten extremely serious over something that isn't even necessary. Lol

Sent from my SM-N910V using Tapatalk

 

Its is only good info for remote start systems and that is it. And just a way for us people living near the equator to verify their cold start systems are operating properly. I have driven out of florida and run into cold weather problems with diesels because the cold start systems are never used or in check here in the SWAMP. Admins can delete thread if determined useless.