riffla

Hi
Have a Chevrolet Transport 1998 (think it's Venture in US)
Having my Check (Engine) warning lit, I thought I'd check the codes for it, but I've now tried two different code readers with no luck. I get power supply and the interface starts. The first one, using a com port and a handheld reader and the second one using a USB connector to my laptop. None of them worked and told me either "no protocol" or "no ECU detected" or something like that.
Now i wonder if there is a specific protocol used in my chevrolet, read something about PVW, but not sure.
Since I get power supply the cars OBD connector works (at least some).

Anyone have any hint or an advice on a good reader/software?

maxxman04

your car is obd2 system. are you using equipment that is for obd2 or obd 1? obd1 will not work for obd2.

riffla

Both were OBD2-readers, actually.

maxxman04

ok. you may check all the ecm fuses, then check the wires and connectors at the diagnostic port. not really sure otherwise, unless the ecm itself is bad.

riffla

Did check the connector pins and cables - and they looked OK. But what I can't understand is which fuses the ECM runs on. According to the handbook schema the ECM connector port runs at the same fuse as the cigarett lighter - and that one is OK.
But still, the ECM fuses are unknown to me.

By the way, the fuse boxes looks exactly the same for my Ch Transport as a Venture 2001 (looked at some pic's for the Venture fuse boxes).

/R

stupidnoob

fyi, unless you have access to chevrolet wiring diagrams labeling out and listing the specific fuse on a circuit... dont go just by what the top of the fuse box says... check all the fuses. Get a test light hook it to ground and touch all the exposed points on the top of the fuse. if you get power on one and not on the other its bad, this way you can check the whole fuse box in 1 minute as apposed to 3 fuses in 1 minute.

If you have a questionable one, sure pull it out and verify, otherwise its a pretty simple operation.

riffla

A good point there, which I will apply next time I need a quick fuse check. But the basic issue, not being able to connect to ECM, has now been demystified. Turned out to be incompatible equipment (those I bought and tested) since the garage guy tonight made a successful connection. So all (hopefully) I need to do now is to go to the store to buy a new Lambda sensor.

Many thanks to maxxman04 & stupidnoob for help!!!

/R

maxxman04

glad ya got it sorted. the update is great too, might help someone else in the future.