Resistor to Fix MAF Error with Cold Air Intake

But... The Prius IS the Pinnacle of Automotive Engineering! :madgrin:

 

This might help:

MONITOR DESCRIPTION​

If there is a defect in the sensor or an open or short circuit, the voltage level will deviate from the normal
operating range. The ECM interprets this deviation as a defect in the MAF meter and sets a DTC.
Example:
When the sensor voltage output is less than 0.2 V or more than 4.9 V and if either condition continues for
more than 3 seconds.​

MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS​

P0100:
P0102:
P0103:​

COMPONENT OPERATING RANGE​

Related DTCs P0100: Mass air flow meter circuit range check (fluttering)
P0102: Mass air flow meter circuit range check (low voltage)
P0103: Mass air flow meter circuit range check (high voltage)
Required sensors/components Mass air flow meter
Frequency of operation Continuous
Duration 3 seconds
MIL operation Immediately (when engine speed is less than 4,000 rpm)
2 driving cycles (when engine speed is 4,000 rpm or more)
Sequence of operation None
The monitor will run whenever the following DTCs are not present None
Mass air flow meter voltage Less than 0.2 V or more than 4.9 V
Mass air flow meter voltage Less than 0.2 V
Mass air flow meter voltage More than 4.9 V​

Mass air flow meter voltage 0.4 to 2.2 V

the MAF is a bridge, with a temperature sensor and a heater in the top two legs, and two fixed resistors in the bottom. An opamp provides feedback to provide enough current into the bridge. You would need to modify the resistors in the bridge, or mechanical restrict the airflow over some of the temperature sensor to compensate for the higher flow and lower temperatures.

 

Perhaps those owners have the advantage of knowing what they are doing.

 

One thought...

Please make sure there are no restrictions to the current airflow as opposed to the original, however little. Nowadays things are set so precise, it takes very little modifications to cause issues. Just the mere change to a different airflow which is cooler could create issues due to cooler air having a difference in mass versus the original airflow.

 

What was the outcome of this? I'm having the same issue with the setup below...thinking it HAS to be a voltage issue. Getting codes P3190 and P3191 with my 'Torque' app ... as soon as I swap back for stock and clear codes...car runs normal. Using the same MAF for both setups, so I know thats not an issue. Do I need to ground the intake!?!



I've already noticed a 2-3 mpg gain just by removing the entire snorkle/silencer from the airbox, I can only hope that it will improve more once I figure out this issue. Once I have the voltage corrected, I'll run the intake tubing down into the lower wheel well under the passenger headlight.

 

"When DTC P3190, P3191 are detected and the remain of the fuel is little, the computer judges the cause as a fuel shortage, and after the next trip, when the supply of fuel is confirmed, it turns off MIL, but the memory of DTC still remains" - but now what?

 

I don't know a lot about this car yet, so looking for a fix for this issue is not resulting with many good results.... A Simple MAP/MAF Enhancer This site talks about finding the signal wire on the MAF and adding a resistor, but I really don't know exactly.

 

Hah... doubt this will work either... How to Bypass the Cold Air Intake Sensor | eHow.com

 

Interesting...



Now... how to add the resistor...

 

In the performance work I've seen done by professional tuning shops (most notable: Norwood Performance- Ferrari Service, Parts and Performance Upgrades), a change in air / fuel delivery is usually done with an ECU remapping. The main reason for this is that the numbers seen by the ECU lose their meaning when the underlying hardware is swapped, ex.: a given voltage will no longer represent the fuel volume it used to given a different injector. Without a proper map, a modern engine will be running with suboptimal power and/or efficiency.

As it has been said in another thread, your MAF is likely sending signals to the ECU that are out of its programmed range. Adding a resistor to the MAF may bring the voltages back into the ECU's range, but how will you know that you're sending the right voltage for a given airflow? You're tricking the ECU into thinking some volume of air is being pushed through the intake, and it's going to work its magic (adjusting fuel delivery and/or ignition timing) accordingly, but it's going to be working on faulty information.

Most likely result: loss of MPG. Least likely result: any performance gain.

It's your $$$...

 

putting that 3" pipe in front of your intake manifold isn't gonna help it breathe more, but it will lower velocity through the maf, which isn't good on an otto cycle. w/ atkinson i wouldn't guess it would help. i would like to check manifold vacuum before choosing larger intake pipe.

 

that was mean, but i like it.
i'd have to say most owners don't know what they're doing. they hire people who know what they're doing, or at least advertise well.

 

LMAO