Code P 1693 ?

[carhauler]

Anyone know what this code means? I think I lost my lift pump again today. Just had it replaced on wednsday. Anyway this is the code I got out of it and engine light is lit. Thanks for any help

 

[Evan A. Beck]

P1693 is a code set when BOTH modules (PCM and ECM) detect the same thing. This is basically a "bogus" code, and doesn't mean much. I have seen it on a lot of trucks, but interestingly, it is ALWAYS present on trucks with shot injection pumps.



The failure of your lift pump will not set a code, as there is no monitoring of it by the ECM.



The P1693 code is nothin to worry about.

 

[JohnB]

It's low voltage to the MAP sensor. The reason I know is because I turned on the key with box hooked up and not the ground, got that code plus a P0236, I think. Service manual says one is low voltage and a companion code in the PCM. It takes a scan tool to remove, but the check engine light will go out.

 

[carhauler]

Thats Kool . One thing i dont understand is the lift pump deal. Two pumps in two days. could it be something else ? I dont have a guage hooked up but it only filled the filter canister once or twice in about an hour. I also check under the vp at schrader valve and same thing. So were you saying it may be the inj pump . Thaks for the response dude

 

[Evan A. Beck]

These lift pumps can be very finicky. I have replaced dozens of them, and more than a few times, the pump is bad right out of the box. One truck I worked on about a month ago had a low fuel pressure problem so I replaced the pump... Ended up going through 3 pumps, and finally got a good one. Strange, eh? Take the pump back and get another one, and keep doing it until you get a good one.



The MAP sensor voltage too low code will turn the MIL on. The P1693 will not. The MAP sensor code is quite common when the truck has an older Banks Ottomind module connected. Seen a lot of them do this...

 

[Diesel Freak]

I have seen that code a couple of times..... It is a little unnerving when the check engine light comes on. I wish I could isolate and fix the cause of the P-1693 code, but for now I will just run with it.



-Cliff