Engine would not start with high voltage at Ox sensor and high voltage DPFE erro codes. Cleared codes engine started and ran 2 days. Would not start, no error codes returned.
Tapped on ERG and drove it home. Started up again. Traded DPFE with other 02 explorer and both ran fine. Sat overnight, theft alarm went off at 7:15 am, engine would not start.
Changed ERG as I had cleaned it 4 years ago, little sticky but working. Started drove out of garage, died. Returning high voltae DPFE. Starts no power. wigled wires around DPFE and throttle. Cleared code, returning high voltage engine coolant.
With DPFE unplugged and key on engine off DPFE 2 leads have 5 and 6 volts.
I'm thinking short in harness. anyone have a likely spot. Where do oxy ,dpfe alarm and engine coolant wires share space?
Not going to be fun.
Started this morning 4 times. Did not trust it, this afternoon without touching it it will not run.
Traced harness back to firewall and removed. Continuity between grey/red brn/wht wires to DPFE. bypassed harness to fix those shorts. Will not run, on to find the next problem. not surprised, clearing error codes should not have made it run.
PCM or another short?
Tested circuits just outside PCM by cutting wires. No backfeeding from shorts that way.
PCM is sending 12 volts to temp sensor instead of 5 volts. Also sending out 6 volts in what should be a variable return signal from DPFE.
dealer cost for PCM with flash about $1k. Ordered junk yard $50 plus shipping.
Started a PCM thread to check out difference in rev to PCM #.