98 Voyager Service engine lamp on but no codes?

Hi-
The Service engine lamp on our 98 Grand Voyager came on and I had the
computer scanned at the local parts store. The OBDII tester says
nothing is wrong, but the light is lit and apparently because there
are no codes, OBDII won't allow a lamp reset.
Anyone ever run in to this?

Thanks- Carl

 

I'd say take it to a dealer or qualified repair shop that knows what
they are doing and has the right equipment to diagnose your problem The
MIL lamp doesn't come on for no reason.


Matt

 

You would think so, but the OBDII tester shows that the processor
believes the light is "off"- in other words, as far as the processor
is concerned, there is 'no reason' for the light to be "on".

-Carl

 

It may not be a good enough unit. Also there are "driveline specific" codes
that only an DRB from mopar can pick up or a snap on unit. Take it in to a
qualified tech with a mopar scanner.
Larry

 

By any chance did this vehicle just pass the 60,000 mile mark?

 

Then it appears that one of two things is wrong:
1. The right tester isn't being used or it is being used incorrectly.
2. The computer itself is bad and may have a failed output.

I'm pretty sure my 96 Voyager has problem number two on the pin that
controls the rear washer. The washer came on and stayed on. I had to
unhook the pump to kill it. The dealer couldn't find the problem and
was blaming a short in the wiring. Well, I unplugged the big connector
to the BCM that holds the pin for the rear washer and then it stopped
pumping. The pump is activated by switching the ground lead as the
pump(s) are powered directly from the power distribution center. It
appears that the output has either failed with a short to ground
internally, or the software otherwise things the pump is being commanded
to be on. Since the HVAC switch panel talks to the computer via a bus
rather than discrete signals, I didn't have the equipment to
troubleshoot it any further. However, unplugging the HVAC/wiper
controls didn't have any affect on the status of the output pin on the
BCM so I'm fairly confident that the issue isn't bogus commands from the
washer switch switch.

It could be that you have the same problem.


Matt

 

there is the trans controller. which can turn on the lite and some scan
tools the (cheaper one's)can't access the codes take it in before it's
too late

 

well thats the problem the ns van is a obd3 emission configuration

 

About 53000 miles ago <g>.

-Carl

 

That makes more sense than the "it's a cheap tester" theory (But, I'm
going to take it over to my friend's garage and see what his
megadollar scan tool says). I was always under the impression that
OBDII was developed to eliminate the need for manufacturer-specific
scan tools. The transmission shifts just fine and all the accessories
work but the van has 100K plus Central New York miles on it, so there
is a good chance that I'm looking at a corrosion or loose plug
problem.

-Carl

 

No, not at all. OBDII was developed with the idea to make the car computer
smart enough so that it can self-diagnose the emissions control systems, so
that inspection stations can plug in a tester that talks to any car computer
and
decides if the car is a polluter or not. It was also thought a good idea to
define
many of the codes common to all vehicles.

But the manufacturers can and do add codes that are far in advance of the
stuff that ODB defines.

Ted