Quote:
Originally Posted by MB-Dude
Where the OBDII output comes from, I do not know. (Again, my R129 Repair DVD is unavailable so I have to rely on others.) Assuming the two ECU’s are identical and after I have a brew or two for courage, I will probably swap the ECU’s to see if the problem moves to the other bank. I do not think it will. I am leaning toward a current theory (one of many!) that whichever computer controls the ‘Ready’/’Not Ready’ signals is the culprit. I suspect that this is also the computer that generates the OBDII output. Perhaps you can research that aspect on AllData.
|
I was ruminating on the OBDII connector wiring theory again, and this probably can't be the issue. I think all the signals that we read off the OBDII connector are sent over the same pin or maybe a couple of them. If the wiring were bad to that one pin, then all the signals that you try to read would be mucked up or dead (I would think anyway). Clearly that isn't the case. Perhaps it's a problem internal to the ECU. While it may be receiving a good O2 sensor signal and processing it correctly, it's output to the diagnostic connector is screwed up for some reason.
But, I can't say anything about your issue with readiness monitors at this time. I don't seem to have that problem.
I'll try to read some more on the possibility of swapping ECU's.
Right now, I'm having fantasies of a tech on the site jumping in and saying, "I've seen this problem before... Here's what you need to do."
I think we've almost provided enough information for an armchair diagnosis.
Brett