Air Flow Meter spec?

[510SX]

Any Nissan Mechanic or guru on duty?

My 91' 240SX threw a code No.12, which is air flow meter circult. I follow my FSM step by step check all the wiring, it turns out ok. Then, I follow the FSM page EC&EF 183; measure terminal number 1 at idle. The spec says it should be 1.0-1.4V, but mine reads 0.1V. Then, I put my spare air flow meter, it read 0.1V at idle also.

Now I am worry, are both of my air flow meter bad or the manual miss print?

anyone has actually done this test or anyone willing to check your working vehicle to verify for me.

Thanks in advance

[DAEDALUS]

Cars are fairly similar in a lot of ways, so I'd say that 1-1.4v sounds right. Measure the reference voltage to ground to make sure you're getting 5.0 volts. If so, then turn the car off and measure the resistance between the sensor ground and vehicle ground. Should be almost nothing.

[510SX]

Cars are fairly similar in a lot of ways, so I'd say that 1-1.4v sounds right.

So the FSM is correct?

Measure the reference voltage to ground to make sure you're getting 5.0 volts.

I don't recall in the manual, to check a terminal for 5.0V. Did I miss something?

[DAEDALUS]

Yes, the FSM is correct. The manual does say to check for a voltage, but I was wrong about the value. Looks like it uses straight battery voltage and not 5.0. 5V is more common, but battery voltage gives a better resolution. Look through the diagnostic procedures. There are instructions for checking all 3 wires--power, ground, and sensed, at least in the FSM I have.

[510SX]

yes, I have checked the three wires yesterday. It has 12V going to the Air Flow Meter. I even disconnected the ECU to check for resistance of the three wires. I am almost positive there is nothing wrong with the harness.

I guess both of my air flow meters were bad?