Low 5v ref

[fixkick]

91 sidekick. Mpi 4dr 4x4 1.6  (what transmission?) stick our auto?


( i bet the VIN shows 92) code "N" is 92.  VIN : S3 T  D  2 1 C  ?  N 4  100001   (M=91)

   New here. Need help!  Super stuck. Been a trying to figure this out going on 2yrs now.

Dropped the 5v ref on my tps. (means 5v does not reach TPS or 5vdc is dead)

Grey red.
Can’t find any wiring issues at all.  
Load tested.  (not a good idea to do that, this power is weak and easy to damage ECU)

Tested for stray vol so on.
Must have missed something but no idea what.
Did find the maf was sending 7.6 back on the sensor wire.  (never good that, 0 to 4v is par)  never 7v, is this sinking crap China MAF> that love to do that?
the may must be marked with 58B00 on this side. or is fake MAF sold everywhere now.
But unplugged it and still lost my ref.
Falls to about 2.5ish.
Then takes a week or two if I’m lucky for it too come back?‍♂️  
And that’s completely unhooked (whole ECU)?from the harness testing it off gator clips to battery.

Did just see that if I only put power to the ecu I would get 12+ v on my grey red wire. (bad ECU this is) that means the 5vdc reg is burned up to HELL

 Even on an older computer that’s shot. It won’t go higher that .08v. (well bad ECU are bad, means nothing)
16 valve engine and ECu.

never seen any 91 ever with 16valves, they started in 1992. so you year told is wrong.
USA answer.
I'm sure this is 92+ car.  you said MAF and first MAF ever is 1992. (USA) the MAF tells me 16valver for sure.

this is a very simple problem  dead +5vdc- reference
it is just a power supply regulator deep inside the ecu, to run sensors.
dead 5v is , pin B4 is dead.  not 4.75 to 5.25vdc, remover all sensors to prove ECU is bad first)
All causes here.
1: bad wiring shorted. (or open,cut or wires) to ECU B4 or any sensor. shorting.
2: shorted sensor that use 5v.  (TPS, ECT. IAT (air temp if present), O2 sensor or if 02 sensor has a relay remove it)
3: A bad ECU.

to diagnose any 5vdc refr, failure, of any kind remove (unplug) all sensor on the  engine, even 02. see my schematic and look carefully.

+5vdcRef fails and blows out (ECU)( for shorted sensor or some 1960s mechanic that loves to hot wire  things and blows  things up.
ECU pin B6

you said MAF so here they are.
all parts the run this EFI.

remove MAF, O2, ECT and if found IAT (air temp sensor) do not skip the calif ,B17 EGR sensor unplug it. if missing and wires to it are shorted , NO GOOD that.

Bench tested, A12/13 at 12v and B1/B2 at ground pin B6 must be 5vdc ( +/- 0.25v variance) if test fails the ECU is in fact BAD. (Regs inside burned up)
I bet this car shows huge DTC errors not code 12  flashing on demand, (DLC diag jumper in place)
Key on (only) the CEL must glow or ECU has no power. (CEL bulb not missing bad or black tapped out as bad boys do)




someone Blew up to H3LL IC117 (I made this drawing , not seen anywhere else on earth)