Engine/Transmission (1998.5 - 2002) Code readers/hidden codes

[Steve Robinson]

I am told by a tech that there could be codes in the computer memory but the "check engine" light may not come on depending on the type of code. Anyone know if this is accurate? Also, can anyone recommend a code reader for my 98. 5?

I am having harder start issues after FASS pump installation and I am thinking maybe the vp44 is sick again. I had no problems until the FASS installation recently. Help! If you are in So. Cal. and have a reader I would really appreciate the help. Thanks all. Steve

 

[FDavid]

I pulled one engine and one trans code without the check engine light being on. Just go down to autozone or something and they will check it for free.

 

[ALepley]

They arent called hidden codes per say. If there is a code in the ecm its either a history code or a code that wont set the check engine light. Some codes wont set the check engine light because they dont pertain to emissions. OBD2 only sets a check engine light when its an emissions related code. If it isnt it just stores it in the ecm.

 

[Gene Heck]

Your FASS is probably putting to much pressure on the VP44 while cranking. Your truck needs to start on reduced fuel pressure if I remember correctly.

 

[monkeyman]

I blew my VP44 years ago when FASS put out to much pressure, watch it, no codes till it happens!
Rick

 

[Wiredawg]

Whut R Presseure Readings?

FASS:

I'm running two original FASS Pumps (on 02 and 03) and see 5 to 7 PSI when I turn to run, see 16 psi cruising and see about 1 to 3 PSI drop at hard throttle. I don't do full throttle after trashing rear seal and yoke on my '02 3500 once. If you are not seeing 5 psi, the fuel line is not brought up to pressure before starting. What do you read for the above conditions on your FASS?



Codes,

I haven't seen list that indicates whether a code set check engine light... I guess I could periodically check. I have a nice code reader, connectors to check all OBD I and II systems. Maybe at oil checks? My experience, code is an indicator of an issue, whether random, periodicm or constant. Auto Zone will read codes for free too. Need a manual or check here to see what code means.



Let us know more info.



Wiredawg

 

[Bob Cochran]

Someone said Auto Zones, etc. in California will not longer read codes. I do not live in California so do not know this for a fact just something I remember reading on here some time ago. Probably worried about some kind of liability. Could hav e been just one isolated Auto Zone too.

 

[Joe Mc]

My initial thoughts were also related to too much psi causing a hard start. When you turn the key to on the pump will cycle to build psi then kick off, wait to start light goes off and you start. During the time you are waiting to start (you do wait to start - yes?) you should see the gage climb and then subside to around 3-7# and after you start it will return to the normal 15-16# based on the pump relief setting. If you see constant 15-16# during the wait period you may have a stuck relay or ??? else going on causing the hard start.

 

[Steve Robinson]

Monkeyman, what did you do to bring the FASS pump pressure back down to a safer level after blowing your vp44 with too much pressure? Also, I thought the excess fuel returned to the tank and it was this process that cooled the vp44. What is it about too much pressure that ruins the injection pump? Thanks for the help, Steve

 

[Steve Robinson]

Wiredawg, at the turn of the key before starting (yes I wait to start) the pressure surges to about 15psi then falls to about 0-1psi for starting. After starting the gauge is pegged (16psi Westach) and I don't know how much pressure there actually is. Hard acceleration drops the pressure to 15psi. but the pressure returns, pegging the gauge again at cruise. I have ordered a 30psi from Genos and that should give me a better idea how much pressure the pump is developing.
What brand/model of code reader do you have? Did it come with a manual which tells you what the codes mean? Where did you buy your code reader? Thanks for the help, Steve