Engine/Transmission (1998.5 - 2002) codes 1693 and 122, truck surging?!

[Beach]

I noticed a slight "miss" yesterday and thought nothing of it. Today I had to drive about a half hour and the whole time it got progressively worse, dropping about 1-200 rpms and coming back. Fuel pressure never changed the whole time so I started thinking APPS..... again. I pulled over when I saw the engine light on and shut the truck off. I checked for codes and came up with the pcu 1693 and ecu 122. I did a quick search and saw that someone said it could be low voltage. I've had the black cover off of it for about 2 years now, just from forgetting to put it back on and was wondering if dust could be building up or something along those lines. Can I spray a cleaner into it to help my issue. I am trying to sell this truck and don't need to be dumping money into it if it's a simple fix. Thank's for any help guy's.

 

[dclassens]

A few trucks back I had the same issues. I had the P0122. Local diesel shop told me it was VP. $2600 LATER I was going again. 9 days later P0121. All codes were APPS related and they then changed that out for $550. Be VERY thankful you have a fuel press gauge as you know it is not VP. I think in my heart it was APPS the whole time and they were wrong but could not admit it, and I could not prove. SEARCH TDR for TIMBO as he has some APPS aftermarket stuff the you may hook into. TIMBO!!!



Dave

 

[BudPhoto]

Did either of you have the temp guage drop while it was surging? Mine is and I have the P0121 code