zagerzelaya

Helow friends, i have a 97 civic d16y5 and it has a p0107 low voltage on map sensor , it supposed that the ecu had to send a 5 volts to the map sensor but only sends about 3.7 volts , so i dont know what to do?
Its the ecu bad?

ezone

Post moved.

Is your voltmeter properly grounded?
Is the ECM properly grounded?

Got full battery voltage at ECM terminals C10, A11, A24?

MAP has 3 wires.....Should be a 5v (reference), a ground, and a sensor return (signal) to the ECM.
Got a scanner that displays live data?
Jumper sensor return to ground and see if live data agrees with 0v,
then connect sensor return to the 5VREF and see if live data shows 5v.

Unplug the TPS, see if the 5v line is also low there too.

Unplug all 3 wire sensors in the car, check if any or all also have low voltage, and see if your MAP reference comes back up to 5v:
MAP,
TPS,
FTP,
EGR lift sensor,
AFR sensor with like 7 wires if yours has it
If you have CVT, unplug the trans computer

(MAP may have its own dedicated 5v supply, so other 3 wire sensors may have no influence on low reference voltage seen at the MAP)

Open the lids of the ECM and look for evidence of leaking capacitors on the circuit boards (google image search 'leaking capacitors' for clues)

zagerzelaya

Yea the tps only has 0 volts with the key in position to start
And the map only has 3.4 volts and it doesn't has continuity in ground wire. I dont have live data scanner im doing this whit a multimeter

zagerzelaya

I check all sensors and only the map and tps has no voltage , im goin to replace the ecu, so here's the thing my car has a p2n-a22 ecu and i found 2 , 1 on ebay it's the same p2n-a22 by 70$ and another one on wrench a part but it's not the same it's p2n-a12 by 30$ i dont know if i can use the p2n-a12 on my car civic 97 hx , d16y5 manual 5 speed.

ezone

Oh you have an HX??? (engine numbers mean little to me without the rest of the car info)
Oooh that's like a class all by itself. AFAIK you can't substitute any other ECM, it's got to be right for the car you have.

The ECM will have to match exact for HX engine and manual trans ........


The Honda number I see in the parts catalog that matches your car looks like 37820-P2N-A22.
The only other choice is for California emissions (P2N-L22) and I can't say for sure if it would work or not.