Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
"no 5v ref. no 5v from pcm. I can how ever unplug top o2 jump asd relay and get a 5v ref."
Can you elaborate on this more? I can see the o2 heaters share same ground as PCM grounds. Clue maybe?
"with everything un plugged im getting 11v at batt 10 going in the pcm and .7v coming out of the 5v ref"
This unloaded circuit test does not test wire integrity.
Backprobe with PCM connected and starter CRANKING and watch the voltage at each of the 4 pins of C1.
I colored orange is hot start or run, Red is hot all the time, and Green is ground.
Another way without necessarily cranking engine over and perhaps faster to check wire integrity:
Substitute a load to check harness integrity. I like to use a headlight bulb for this test. Test at disconnected harness C1: put the bulb between PIN 2 and PIN 31/32 and between PIN 22 and PIN 31/32. Compare the brightness to the brightness when you hook it up straight to the battery.
thanks for the input. I liked the headlight idea had one laying around. good power on 2 and 22 using both grounds, and using the batt. good power coming in still nothing on the 2x 5v wires
one thing I have noticed is my underhood light works one time and not another like its shorted I have done tests with it working and not working nothing ever changes
cant remember how I did the o2. had someone helping me. I had everything unplugged and no 5v ref. jumped the asd and nothing. I forgot 1 02 at the top of manifold. unplugged it jumped relay and had 5v and climbed to 10v. I haven't been able to do it again. I might have messed that test up and got a bad reading. I can only jump the relay with key off not on the last time I tried it
