I need help from someone knowledgeable reading this group.
2003 1500 2wd 5.7l Hemi. low mileage 48K, oil changes done at 3000 to
3500 or 6 mo which ever comes first.
Problem: Intermittent check gauges light upon starting, has no oil
pressure reading on the gauge when this occurs.
Shut it off wait 5 sec and start again oil pressure gauge registers
pressure and no light. Hot, cold makes no difference
Could be bad sending unit but I would think bad unit would be more
consistent in failure. I am leaning toward bad connection somewhere.
I have Factory Service Manual and know which pin and connector on the
PCM the wire from Oil pressure sensor goes to but for the life of me
can't find the output from the PCM to the instrument cluster or any of
the gauges in the wiring diagrams for the instrument cluster so I can
check the connectors for crud.
Any one got any other ideas and/or links to good wiring diagrams for
Does Dash gauge really show Oil pressure or is it just a signal from
the PCM that there is oil pressure?
I don't know if the sender is a switch or a variable resistor since it
is a one wire (on a two pin connector) Diagram indicates its variable,
I do know it should get 5V from the PCM. So is the PCM reading current
flow or voltage drop?
I just found in the service manual that the oil pressure gauge gets
its data via the PCI bus so now I know that the little 'puter in the
PCM is talking to the little 'puter in the instrument cluster via the
FCM. That about rules out a bad connection after the PCM since
everything else seems to be working okay. (Yes I was reading while
composing this, It some times helps me to sort out the solution to a
problem to work that way.)
I think I'll try a meter on the sender for ohms engine off then
running and see what the difference is I don't want to spent 30 bucks
for a part and not have it fix the problem.
Happy Camping. snipped-for-privacy@NOPANTS.juno.com
Remove NOPANTS To reply by direct E-Mail;
2003 Dodge 1500 QC SB Hemi, A/T, Tow Package, 3.92 gears (11 mpg Towing)
2001 Aerolite 21RDB 21ft TT (Scales 2900 dry)
Linux/Unix is user-friendly.
It's just very selective with who its friends are.