Why don't you start by telling us some specifics about your truck. How are you pulling codes? It needs to be done with a scan tool, then get back to us. You will have some sort of code if you triggered the cel. Why did you have to disconnect your ecm?

 

The truck is all stock as well.

 

The truck is a 1999 2500 4x4 slt 6 speed. I had to disconnect the ECM to be able to get to the oil pressure switch, I don’t have a scan tool but I took the truck to autozone and Midas to use their scan tool and they were not able to pull any codes! They scanned the truck multiple times and still no codes the only thing the guy kept telling me was that the scanner was not able to get a connection or a reading from the body control unit. Also the truck did not have this problem before I replaced the oil pressure switch.

 

Happened to me when I replaced my ecm. Most likely just need a better code reader to clear codes

 

Did you have the same problems with the wait to start light as well? Also Midas used their like crazy expensive most in-depth scanner they had!

 

if the bats were still connected when you disconnected the ecm I believe that would trigger the cel

 

delayed wait to start does not bode well for your ecm either

 

Ugh. Double check to make sure everything is plugged in correctly and never disconnect your ecm with the battery cables still on. Take your truck to a dealer and get a drb3 on and check for codes.

 

I had the batteries Disconnected but I didn’t put any dielectric grease on the actual plug so I will try that and see if it works. Thanks for all the advice to everyone who posted on here so far! I’ll update the post when I figure out what the problem is.

 

The wait to start indicator is directly controlled via the ecm. A delay indicates an ecm problem unfortunately. Hopefully a better connection with dielectric helps but not likely imo

 

Exact thing happened to me when I replaced my bad ecm. My ecm had symptoms before going out tho. So I doubt yours just happens to go out after unplugging it. After I installed my new ecm I got a CEL, and wait to start never came on. Cleared codes and put on dielectric grease, and wait to start came on for about 20 second, after about 20 seconds. Ever since it’s came on right away like it was supposed to. If you do need an ecm I recommend

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