2nd Gen Non-Engine/Transmission got codes 1694, 1693 & 1687

[SSolderitch]

I got these after trying to figure out why I don,t get a wait to start light or a pump pressure bump? Bad ecm, map sensor, AIT sensor or other? any ideas?

 

[MAllen1]

Your 1687 is a code that comes from the instrument cluster, from what the service manual is telling me. The 93 and 94 codes are pcm codes. The way they word it in the service manual makes me want to advise as to cleaning the plug going into the pcm and the plugs going to the pcm to both pumps (lift and injector). You didn't say if your truck was running or not, but, if the truck is running up to par, clean the connectors and put in something to keep dust and such out.

 

[SSolderitch]

truck starts and runs fine and no MIL light. I didn't know I had a code until I did the 3 key thing. Trying to solve a no "wait to start" light & no fuel pump 3 second run for pre-start pressure. Fuel pressure builds just fine after start, just not before. My guess is I don't have grid heaters, Was in the high 50's Sat morning & still no light.

 

[SSolderitch]

update: put electrical contact cleaner on all the PCM contacts, let sit overnight. Now I only get a P1693, but still no wait to start light.