Did you know that when the MAF sensor fails in your vehicle, the ECM has an internally programmed emergency mode that maintains a constant reading in grams per second for the intake air value? This is because if the vehicle stops sensing correctly or loses communication with the MAF sensor, it won't be able to generate the necessary mixture for proper combustion.
This fault is easily detected when the check engine light comes on, and the scanner displays fault code P0103, which indicates a high signal from the MAF sensor. This can be due to several reasons, such as a short to positive, a damaged sensor, a malfunction, or a loss of communication.
But what if no fault code is generated? What if the scanner doesn't generate a fault code? How can you check the status of any sensor?
Well, in this same example, it's easy to see without needing to measure voltages with a multimeter or verify signals with an oscilloscope. You simply need to connect the CanBus Multiplex Trainer and, using its new software section, identify the hexadecimal data it's providing. For example, in the image shown in the photograph, you can identify them as follows:
MAF AIR FLOW RATE: 7E8 0X41 0X10 0X05 0X2D 0X00 0X00
which is equal to 13.25 g/s
Then you can verify that communication is successful and the data is within the expected range without any garbage hexadecimal values or short circuits that alter the data frame.
However, if you find that the data remains fixed and unchanged even when the vehicle accelerates, you can realize that the vehicle has entered limp mode and will not exit unless the fault is fixed and the DTC is cleared.
And if the check engine light doesn't come on, but your vehicle loses power when accelerating, you can check the status of the sensor or component causing the fault using freeze frames that will only be displayed if there is an existing fault in the vehicle, even if it is not shown as a fault code on the scanner.
Now, checking sensors and actuators without a multimeter or oscilloscope is easier with the CanBus Multiplex Trainer Pro Plus software.
