Thanks for your help, I took the fusebox out and tested for continuity from obd pin 1 to B2 and to B3 on the B block connector under the fusebox, all good.Ya, can't add it if you can't talk to it. What else will make a UEC seem dead when it isn't? UEC communicates on I bus (single wire) so a bad connection or two can drop modules off the bus. No power would do the same. Beyond that the failures get dicier. Here's an I-bus diagram. OBD port goes to CIM which goes to UEC via MIU. Note that failure in H102-1 can disconnect both REC and UEC from I bus (EDIT: and a few other things).
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