Just checking, since maybe I misread - the pinpoint tests E1-E6 appear to be for checking that the wiring loom is OK - no open circuits and no shorts to ground or high voltage for the two wires between the O2 sensor element and the ECM. So my interpretation is that the ECM and O2 sensor should be disconnected for all tests - as in the preliminaries for test E1 - 2. and 3. disconnect EM21 (to O2 sensor) and EM82 (to ECM). In that case, these specific tests, as opposed to something else you may have tested, don't test the ECM.

 

I had a customer car with a VVT actuator fault that was at another shop for diagnosis.(P1384)
They could find no fault with the VVT actuator or harness circuit.(they ran external wires from ECM direct to VVT actuator, NO CHANGE)

I swapped out a spare ECM and performed an IMMOBILIZATION SETUP.
Success! I put the wires back to OEM and disconnected the parallel wiring from ECM to actuator.

I wrote FAILED VVT semiconductor P1384 on the ECM and thew it in the recycle pile.

Internal failures are not common but I get them once-in-a-while.

 

for extra clarity:

In my interpretation (maybe wrong), the pinpoint tests on the wiring are to test the wiring without sensor or ECM connected, so that the wiring can be isolated and eliminated/confirmed as an issue
- if the ECM or O2 sensor is left connected, then the test is not being performed as intended
- you can replacement wires, per motorcarman, to double check

Could the ECM be faulty? Yes
Is it likely - No, IMHO - best to eliminate all other possibilities first, as you are doing
How to test ECM to determine if it is faulty - follow procedure per motorcarman
If it is faulty, can it be fixed? Unlikely, just use the replacement ECM, as used in the test
- the most common AJ27 ECM failure is a power semiconductor (bipolar junction or MOSFET), per motorcarman, and that would be potentially fixable (replace device). Early AJ26s often have bad electrolytic capacitors, but not often for AJ27s (yet).
- I don't think that this fault involves a power semiconductor - I think it would likely be an issue with connector EM82 (fixable), or a faulty track on the PCB (open or short), or a dud IC 403 (proprietary Denso wideband O2 sensor processor)
- the O2 wideband sensor is connected directly to IC403
- for reference, I checked on a spare ECM for resistance to ground and 5V and 12V for EM82-4 and EM82-10 and on that ECM there is no measurable connectivity/resistance to any power/ground ( > 2 M ohm at least)
- for reference, see below image (rough guess at circuit). O2_US_V_A connects to EM82-10, and O2_US_I_A connects to EM82-04


IC403 connections