TAS Adjustment (Already moved it!)
 

So I already tried adjusting the TAS since it seemed like the logical thing to do. Then I read on this forum (and everywhere else) that that should never be done. How do I readjust it back to factory setting?

Update:

Voltage test on all three wires of the TPS harness. Tested all three due to ALLDATA's info being inconsistent. Looks like I have a short to voltage on the ground side AND a low ref voltage on the power side. Thoughts?

All readings done key on/engine off.

TPS plug------Wire Color---PCM terminal---V spec------------Actual

A-------------Brown/Red-------4E--------£ 1.0 V -------------2.038 V
B-------------Blue/Yellow------3D--------Variable-------------1.897 V
C-------------Green/Red -------3I--------Ref (5V?)-----------1.479 V


*according to alldata wiring diagram TPS wire B/R is connected to PCM ground terminal 4E. However, according to alldata's TPS Adjustment Procedure the harness terminal A is spec'd at 4.5-5.5V. I think they have their connector end view printed backwards.

MIL on, battery light on
Codes stored
P0505, p0100. p0115, p0110, p0120, p1195
Cleared codes, started engine, codes came right back

Freeze frame data shows;
fuel sys stat B1- OL, Fault
fuel sys stat B2- 0
load 83.92% at idle (835rpm)
ECT -39*C
STFT and LTFT 0%

The low reference voltage looks like the culprit to me. Not knowing alot about car ecms, but 28 years in PLC controls, and with troubleshooting some vehicles. The reference voltage as I see it, one is ground, one is reference (also to me the reason for that is two fold, one to check for the proper voltage to the third wire, actual position). Why the reference voltage is low, IMO ground issue. Is the cel on, and what is the code?

I added the stored codes to my original post. All of them are circuit faults in various sensor signal wires (IAT, TPS, ECT, MAF, IAC (sorta)). Based on the variety of systems and the similarity of symptoms I'm guessing the PCM is defective. Looking at the wiring diagram all of these sensors share a common ground.

However, I still have the throttle screw reset issue and a battery trouble light illuminated on the dash to deal with.

The best part is that all of this is completely my own stupid fault.:cool:

Given the rest you state, I'd have to go along with that.

Thank you, Kevin.

Replaced ECU with used one. Reset TAS via RPM with AC, lights, and fan on high to 750 RPM. All off RPM engine idles at 900 RPM. Purrs like a kitten, no codes!:cool:

great!https://www.mazdaforum.com/forum/ima...ons/icon14.gif