The Diesel Stop banner

1 - 3 of 3 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I'm working on a 1999 F350 7.3 DSL. It misses pretty bad. I ran all self tests with the tuner installed and on the KOEO test I found hard fault P1298 present. I was sent to PPT-KA1 and was advised to replace the IDM. When I tried running the KOEO injector electrical test and when the test had finished P1298 was also present there. Everyone knows these modules are not cheep or returnable so I tested further. I uninstalled the hypertech and ran the same tests. Now with the tuner removed there are no DTC's present. Only when I run KOER cylinder contribution test I have Dtc's for #'s 4 & 8 balance. Has anyone seen this P1298 present with a tuner installed? Any advise on this issue? A faulty IDM can cause the injector DTC's but the IDM DTC has not returned yet.:icon_rolleyes:
 

·
Super Moderator
Joined
·
25,403 Posts
I have a tune flashed on my PCM (DP tuner 80E) and have seen the P1298 IDM failure code on occaision, but have not had any issues with running. I also have done the Joe Servo Mod to my IDM (higher output voltage), that may weigh in to why I've seen it. Again, I've never had issues that would point to a failed IDM.

Used IDM's are aboutr $150-200, so you could go that route, or you could try a known good IDM from another truck if the one you're working on still has issues.

The Grey Ford recall CPS will cause a CCT fault on #8 and sometimes #3 cylinders, although I haven't heard of issues with #4. I had a grey CPS in my replacement engine and it popped the #8 & #3 fault codes, but they went away when I changed back to the original International CPS that the truck came with. It also improved the mileage by about 2 mpg with no other changes.

Your #4 CCT code could be the cause of your missing.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #3
Thanks for the info. I tested more after removing the tuners calibration and found #4 is dead and #8 is weak but still contributing (seems about) 50% - 75% of what it should. It is the aftermarket program causing the P1298 DTC. I've never compared mpg between black and grey crank sensors. Good info though. Thanks.
 
1 - 3 of 3 Posts
Top