Howdy folks,

TLDR:
Faulty ecm runs lift pump without starter bump. also DieselACS out of Hileah FL is a super good company to deal with for ECM issue.

I am here to report an interesting finding of a failing ECM that I had not seen here or anywhere before.

First and foremost, I was dealing with the dreaded WTS delay, and it finally got to about 8 seconds or more before it kicked on, so I bit the bullet and ordered a exchange ECM from DieselACS out of Hileah FL https://www.dieselacs.com

The service was friendly, and the shipping was extremely fast. Ordered Friday, and at my door tuesday morning.
I replaced the ECM, and this is where I realized my old ECM failed in 2 seperate ways!

My old ECM would have a 8-10 sec WTS delay, and after the WTS light would extinguish, the lift pump would prime.

It did this every time, and I realized this isn't normal behavior when I tried to refill the fuel bowl after my ECM replacement, and the new ECM didn't run the lift pump after the WTS turned off. I have to admit, this is when I learned that I it isn't supposed to run the lift pump until the starter bump.

Bumped the starter a couple times, calibrated the apps, and the truck runs MINT! hooked up a OBD scanner, and all was well there too.

Hope this will help someone in the future.

Phil

Good to have another source for ECM repairs. Also, glad to hear that your truck is running well.

Just for clarification, the ECM does run the lift pump for about 1/4 second when the ignition switch is turned on. If the starter is bumped and then the key is released, the lift pump will run for approx 25 seconds.

From the FSM (2002):

The transfer pump is self-priming: When the key is first turned on (without cranking engine), the pump

will operate for approximately 1/4 second and then shut off. The pump will also operate for up to 25 seconds after the starter is engaged, and then disengaged and the engine is not running. The pump shuts off immediately if the key is on and the engine stops running.

• John

TM,

I agree that it should prime for 1/4 second. I am saying that my faulty ECM ran the lift pump for probably 20 seconds once the WTS light kicked off, which is NOT normal behavior.

But yeah i found it strange so i figured i would post here, as this is a phenomenal research and knowledge repository for vp44 knowledge!