98 Voyager Service engine lamp on but no codes?

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

there

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

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

About 53000 miles ago .

-Carl

problem

processor

incorrectly.

connector

stopped

commanded

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