The mass air flow (MAF) sensor on your 2.5L 6 cylinder Suzuki Verona can be tested with a multimeter to see if it's bad or not.
It's a very simple test that's done with a multimeter and in this tutorial I'll show you how to do it.
Contents of this tutorial:
Symptoms Of A Bad MAF Sensor
The mass air flow (MAF) sensor's job is to measure the amount of air the engine is breathing. With this info your Verona's powertrain control module (PCM) can now inject the correct amount of fuel into the engine (among several things).
Because the MAF sensor is such a crucial component of your Verona's engine management system, when it fails it wreaks havoc on your engine's performance.
Here's a list of the symptoms you'll see with a failed MAF sensor:
- Diagnostic trouble codes (DTCs):
- P0101: MAF Sensor Performance.
- P0102: MAF Sensor (MAF) Low Input.
- P0103: MAF Sensor (MAF) High Input.
- Doesn't pass the smog check.
- Engine idles rough.
- Engine takes forever to start (extended cranking time).
- Engine doesn't start.
- Black smoke coming out of the tail-pipe as engine runs.
Let's jump into the first test in the next subheading.
TEST 1: Checking The MAF Sensor Signal
As the mass air flow (MAF) sensor measures the air the engine breathes, it creates a voltage signal. This voltage signal increases the more air enters and decreases the less air enters the engine.
You and I can tap into the signal wire with a multimeter and observer theses changes. The wire that carries this signal is the yellow (YEL) wire of the 3-wire MAF sensor connector.
NOTE: Be careful and take all necessary safety precautions! The MAF test in this section is done with your Suzuki Verona's engine running.
These are the test steps:
Set the multimeter to Volts DC mode and probe the YEL wire of the MAF sensor connector with the red multimeter test lead.
The YEL wire is the one that connects to MAF sensor pin B in the illustration above.
NOTE: You'll need to use a tool like a wire piercing probe to access the signal inside the wire. To see what a wire piercing probe looks like, go here: Wire Piercing Probe.
Ground the black multimeter test lead directly on the battery negative (-) terminal.
Have a helper start the engine. Wait for the engine's idle to stabilize and observe your multimeter's voltage reading.
With the engine idling, the voltage reading should be about 1.5 to 1.8 Volts DC.
Now, have your helper accelerate the engine. The voltage should increase.
At around 4,000 RPMs, the multimeter should register to about 3 Volts DC.
Decelerate and accelerate the engine several times as you observe the multimeter
Your multimeter should register a decrease/increase in voltage as you decelerate/accelerate the engine if the MAF sensor is good.
If the MAF sensor is bad, the voltage will be stuck at a certain number no matter how much you accelerate/decelerate the engine.
OK, let's take a look at what your MAF sensor test results mean:
CASE 1: The MAF sensor produced and increasing/decreasing voltage signal as you accelerated/decelerated the engine: This tells you that the mass air flow sensor is OK (not defective).
CASE 2: Your multimeter registered voltage, but it did not increase or decrease as you accelerated/decelerated the engine: This confirms that the mass air flow (MAF) sensor on your 2.5L Suzuki Verona is bad. Replacing the MAF sensor will solve the MAF sensor trouble code lighting up the check engine light.
CASE 3: Your multimeter registered 0 Volts. This usually means that the MAF sensor is fried. To be absolutely sure, I suggest confirming that the MAF sensor has power and Ground. If both (power and Ground) are present, the MAF sensor is bad. To test for power, go to: TEST 2: Verifying The MAF Sensor Is Getting Power.