What specific codes are you getting, by pin? You shouldn't have to disconnect the battery to clear them. They need to be cleared within a few seconds of the reading, then ignition off after each clear.
The wiring harness is tested by inspection - do you see any crumbling insulation at the end points on the top front of the engine? On the ETA it's insulation, not insulator, in other words the same issue as the upper harness - the insulation crumbles and causes shorts. I'd focus first on reading and clearing the codes, and the upper harness inspection. The OVP is behind the battery, fairly easy to get to. Those two part numbers should both be good - the EPC shows them as interchangeable.
Hi deanyel, the codes that I was getting was NOT consistent. Here are the detailed list:
Pin #3 (continuous fuel injection): code 10 (only showed once, the 2nd time I tried to read it, the code was gone without me even tried to reset it)
Pin #6 (SRS): code 8, 9
- Code 8: voltage supply interrupted
- Code 9: SRS Warning Lamp (with flashing SRS warning lamp Impulse counter scan tool button held too little time to read out the DTC memory or too long or erase DTC codes. Reread codes).
Pin #7 (air conditioning): code 1 (should be "no fault found" right?)
As for the wiring harness, I do not see any serious "crumbling" insulation at the end points on the top front of the engine. They just look a bit rusty and old at the end points (I will try to post some photos later). The car has always been garaged, and never met any snow - living in sunny cupertino california area for the past 17 years. I agree with you that I also want to focus first on reading and clearing the codes, but I can't seem to be able to read the codes consistently with the same results every time, and I can't seem to be able to "clear" the codes (even by disconnecting the battery for more than 1 hour). Thoughts or comments on this?
I will try to see if I could locate the OVP (behind the battery) by myself. When you said the EPC shows them as interchangeable, what do you mean by EPC (sorry about this stupid question)? Also why would people recommend the new part 000-540-67-45 in other threads? Is there a special reason for this? Thanks again!