i got 3 codes this morning on my truck sometimes it will run good and then sometimes it wont. first code is p0523 oil pressure sending unit voltage too high.and p1689 no communication between ecm and inj pump module.and last p1693 generic fault indicating a fault in the bus or pcm/ecm interface any ideas how to fix i already checked grounds and connection goin to pump thanks aaron

 

that dosnt sound good, the last couple trucks i've seen with the 1689 code have ended up being bad injection pumps...only thing that i can think for you to do is check the voltage on pin 7 i think it is coming out of the harness when it plugs to the pump, if i remember right its susposed to have atleast 8v on it....maybe someone else will chime in that knows for sure

 

ok I already checked it and it showed 2.56v and I read up on internet to go by a p0215dtc circuit check. Thanks Aaron

 

Yap your inj pump gave up.

 

When checking voltage on that wire on injection pump plug put the red wire off meter on the red and light green wire and the black on ground?? Right

 

i've neved looked at the color of the wire i allways just stick the voltmeter prob into the plug on the end of the harness and yes ground the other side....with the key on

 

well its got 12.49 volts so i assume my pumps bad cause everyone already told me p1689 usually means bad pump and ive already put a new lift pump on about 3 months ago.