[toon]

The wait to start light in my truck has stopped working and the lift pump doesn't prime for 2 sec when I turn the ignition on, it also doesn't run for 20 sec when I bump the starter, but I have 20 psi of fp once truck is running.
I have seen the wts light delayed a couple of times in the past and the lift pump doesn't always prime when you first turn the key.
I checked my alternator for AC noise using one of mopar1973man videos on youtube and it showed 0.05 V I read its still within the normal range.
I measured the voltage going to the grid heather relays and it reads 4v with key off and 6v key on, it doesn't switch the relay on so the intake heater isn't working :confused013:
I am leaning towards a broken ECM any way to confirm this?
I also recently changed my CPS but the problem didn't start right after but a couple days later.
thanks for your help.

btw truck is a 1998.5 auto

 

[mahdey]

when the WTS light does not come on, will the truck start?

 

[toon]

Yes the trucks starts and the wts light never comes on anymore.

 

[CumminsGuy65]

any codes???

 

[toon]

I checked the codes after I checked the grid heater relays so that might explain 2 of them.

P1693
P0234 turbo boost limit ex (get this code all the time)
P0380 #1 Intake Air Heater relay control circuit
P0382 #2 Intake Air Heater relay control circuit (get this code all the time)

 

[CumminsGuy65]

well no ecm codes is good news. sounds like its just your grid heater is the issue

 

[Off-road]

just a question, but did you check that the WTS light is still good? ie is the light burnt out?

 

[CumminsGuy65]

yea def check the bulb haha^^ good idea off-road. always start with the easy stuff

 

[toon]

I haven't checked the bulb yet even if its burnt out it doesn't explain that the intake heaters aren't working and the lift pump isn't priming :confused013:
Do I just take the cluster out and open it up to check the bulb?

 

[Mopar1973Man]

If there is no wait to start there is no software booted in the ECM. This is a sign of the ECM RAM is damaged and having troubles booting up.

Even if the bulb is bad there is a P0381 code for a burnt out WTS bulb.
Mopar1973Man's Dodge Cummins Articles - P0381 Wait To Start Lamp Inoperative

So now I would suggest you look at AC noise levels and verify your charging system because the main reason for ECM's to cook is the alternator feeding it way too much AC noise.

 

[Ramitt]

I know in my 98 dakota if you would hold in the odo/trip button and then turn the ignition to the on position(release the odo button after key is turned on) it would start a test of the gauge cluster(lights and gauge operation). Not sure if this works on rams or not? I would go out and try it on my truck but my batts are pulled.

 

[CumminsGuy65]

Yes it works^^

 

[Mopar1973Man]

I know in my 98 dakota if you would hold in the odo/trip button and then turn the ignition to the on position(release the odo button after key is turned on) it would start a test of the gauge cluster(lights and gauge operation). Not sure if this works on rams or not? I would go out and try it on my truck but my batts are pulled.

Yea...

 

[toon]

I used this video to check my ac noise.
and it showed 0.05
is this to much? and did it fry my ECM?
How to check Dodge Ram Alternator for leaking AC waveform - YouTube

 

[Mopar1973Man]

I used this video to check my ac noise.
and it showed 0.05
is this to much? and did it fry my ECM?
How to check Dodge Ram Alternator for leaking AC waveform - YouTube

Double check at the alternator battery terminal.

Normal is 0.01 to 0.02

Your 0.05 is getting marginal. Double check like this article.

Limit is 0.10 volts ac.