New PCM plugs and wires? hun?
new harness ,why? in a fire or wreck? running off road?
or did you mean, new PCM, new spark wires, and all new 02s sensors' It wont be a bad PCM , sorry, 99% are good.
the PCM never lies. it measure this and does a test and if it fails there is a circuit fault.
the why to understand, DTCs (have a FSM factory serv. manual)
and read how the test works. or do the tests it tells you do to
to discover true cause)
i have this car v6 3.8L: and 6speed and the FSM, book.
O2 SENSOR 1/1 CIRCUIT HIGH
1/1 means bank 1 , front sensor (upsteam)
bank one means right bank, cylinder 1 side.
what does HIGH mean?
what is not clear is which side is failing, heater or CELL
this test is the CELL pin (oxy out)
the test (called a monitor) finds that pin 4 is stuck at 5v.
the o2 must be 0 to 1volt at all times.
if stuck at 5vdc then the ground is open to CELL pin 3 (wire cut)
or the 02 sensors is bad. (open)
do you know how to back probe? a skill that is must for all modern cars. use needles with your meter. (DMM) (leather needles work in a pinch sold at walfart for 1buck) needle probes are 10x better
key on and back probe pin 4, if at 5vdc or more(or near) it's wrong.
btw page 2891 shows what to do in the FSM. yah 7000 pages.
I think this pin floats to 5v if the wire is cut.
fail 2 is that pin 4 is shorted to voltage ,well , the heater runs off
of 12v and all cars (bad service) the 2 wires melt and short.
here ill list all 4 pins (key on)
1- 12v heater.
3 - ecu quite ground to 02 (cell minus)
4- CELL + out (this is the oxy signal)
pin 4 must not be at 5v or 12v, but 0 to 1 volts.
at key on or running.
one more FSM quote
Measure the voltage in reference to ground, not the (K902) O2 Return Upstream circuit.
that means pin 3 to 4, is measured for best accuracy
but 5vdc or 12vdc is gross wrong .
if the o2 is new (is)
then this quote covers most fails on most cars
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact
in the Oxygen Sensor and Powertrain Control Module connectors.
here is the wiring.
if you need more photos full size or more tests.
or have questions, ask, i'm a retired ET, (controls systems , PLCs +)
see FSM here
on CD (best of best)