Engine/Transmission (1998.5 - 2002) Code P1693 ?????

[erobb]

In another post on this forum, I was expressing that my fuel economy had went down over the last several months and I figured it was time for new injectors. someone replied to say check for code 216 with a scanner it is the advance part of the VP44 could be bad thus affecting fuel economy. Well I checked codes with a scanner and I came up with only 1 code it's P1693--'DTC detected in PCM or companion module' I used my father-in-laws scanner it's pretty nice, this is all I could get. the truck starts and runs well, the Check Engine light is NOT on. Can anybody help.







98. 5 Reg Cab, 4x4, 3. 55's, 5-speed, 256k, original VP44, Pensacola Diesel +50 HP injectors, 4" turbo back exhaust, Van Aaken V-5 box.

 

[sfritts]

My 98. 5 has had that same code number for three years, and it is always in there when ever I check it, but my say's there is an error detected in the tachometer curcuit. truck runs fine mileage is 17-19 with winter fuel.

 

[erobb]

I got to thinking about it after I put out this post and it seemed like I scanned my truck a couple of years ago and got the same thing, just sort of forgot about it over time. I also get 17-19 mpg, I have only broke 20 on 1 occasion, when my wife's car broke down just before a planned weekend get away, we had no choice but to take my truck. We drove back roads keeping speed around 55-60 mph for a 4 hour trip, I got 20. 2. A lot of guys on here talk of over 20 I've even seen 23-24mpg kicked around. My truck won't do that, unless I have something wrong somewhere. Thanks for the reply.

 

[Diesel Dummie]

It is just a companion code, letting you know something has tripped in the past, like sfritts aid it could be someting as small as as dirt on a sensor, but if thats it i wouldnt worry about it, pump code will be

0216 along with 1693, thats why they call it a companion code. Chad

 

[JLandry]

... I got 20. 2. A lot of guys on here talk of over 20 I've even seen 23-24mpg kicked around. My truck won't do that, unless I have something wrong somewhere. Thanks for the reply.

erobb,



Your fuel economy doesn't sound unreasonable... there are so many variables that can affect it. When I had 3. 54:1 axle gearing on my 2WD truck, I typically averaged 20-21 mpg commuting mostly on the freeway. I once averaged slightly over 24 mpg on a summer trip in south central Oregon driving 55mph over relatively level terrain. Now that my truck has 4. 10:1 axle gearing, I'm averaging about 18. 5-19. 5 mpg freeway commuting in colder weather.



One thing that can affect your fuel economy is the IAT (Intake Air Temp) sensor on your engine. Others have reported significant fuel economy increases after replacing theirs.



Best regards,



John L.

 

[FLynes]

... One thing that can affect your fuel economy is the IAT (Intake Air Temp) sensor on your engine. Others have reported significant fuel economy increases after replacing theirs...

I am one of those... my mileage jumped up in a big way... . right now I'm at 340 miles and at half a tank. Before I replaced the IAT (which was crudded up), I was getting about 363 miles to a tank.

 

[rweis]

I'm comming up on 100k and ordered a spare IAT to change out at 100k. I will clean the old one and keep it as a spare (or if a TDR mrmber needs a loaner one in a hurry). I'm starting to think that to help keep mileage up the IAT should be cleaned / changed ~ 100k. Cost was $32. 22 which included shipping etc. Cheap preventative maintenance if has ANY positive effect on the mpg.



I know this is getting off the thread subject, but if you drive by your overhead mpg (I know it may not be very accurate to what mpg really is, but it is ok relatively) you will then know what your truck does on a day in day out basis over the kinds of roads you drive at the speeds you drive and the loads you carry. When you make a change (clean the IAT in my case), you will have something to compare against.



Bob Weis

 

[erobb]

Thanks for the info guys, I have cleaned my IAT in the past I think I did replace it once but it has been a long time ago. I'll try to pick up a new one later this week and get it put in just for preventative maintenance. Besides with diesel fuel at $3. 86/gallon around here what's $32. If it helps you get even . 5 mpg more.

 

[Huff N Puff]

It means there is a code in another module

In another post on this forum, I was expressing that my fuel economy had went down over the last several months and I figured it was time for new injectors. someone replied to say check for code 216 with a scanner it is the advance part of the VP44 could be bad thus affecting fuel economy. Well I checked codes with a scanner and I came up with only 1 code it's P1693--'DTC detected in PCM or companion module' I used my father-in-laws scanner it's pretty nice, this is all I could get. the truck starts and runs well, the Check Engine light is NOT on. Can anybody help.







98. 5 Reg Cab, 4x4, 3. 55's, 5-speed, 256k, original VP44, Pensacola Diesel +50 HP injectors, 4" turbo back exhaust, Van Aaken V-5 box.

You need to scan the other modules,usually the PCM.