You didn't know the difference between the data link connector and the service check connector. :chuckles:


If I were you I'd reset the ECM, start the engine and turn on the headlights. If DTC P1298 isn't indicated then it was just an intermittent failure. If the check engine light returns, disconnect the ELD 3P connector, turn the ignition to ON (II) and measure voltage between the body ground and the ELD 3P connector terminal 1. There also could be an open in the wire between No.15 Alternator SP sensor (7.5 A) fuse in the under-dash fuse/relay box and ELD.

I just threw a PO420 for catalyst efficiency yesterday after using sea foam. I reset the ECM and it didn't return. Also, I have never needed a diagnostic code reader, waste of money in my opinion.