Hi guys, today I’m going to show the procedure for a car engine cylinder drop test/ power balance test. This will show how to use Autel MaxiPRO MP808TS Scan Tool to find a misfiring cylinder.
This time I’m taking a 2008 Toyota Matrix for test, but this procedure may apply to most vehicle makers.
Connect Autel MP808TS with OBD, start the car, press
Diagnostics >> Toyota >> Automatic selection >> Read >> OK >> Yes
Diagnosis >> Control unit >> Engine and ECT >> OK
Active test >> Control selected cylinder fuel cut
This active test controls fuel cut to select cylinder.
This test cause a rough idle or the engine to stall.
Operate with ignition ON, engine ON, shift range is P(AT) or neutral(MT).
For CNG vehicle, perform this while engine is running using gasoline for fuel.
ON-select cylinder fuel cut.
OK >> All data
Note: Modern cars would typically compensate for a dropped cylinder so RPM alone may not be most reliable.
Right down here you can see these are the 4 cylinders/ injectors: #1, #2, #3, #4.
Press #1, you can notice the car is running rougher.
Press #2, #3, #4 in turn, all are still the same level of vibration.
So this car doesn’t have any problems with cylinders.
If you press any button and the sound of the vehicle doesn’t change, that’s the problem cylinder.
Using Autel MP808TS Diagnostic Tool in this way just helps you identify what cylinder has the problem, and then you can go on to do further diagnostics to confirm where the misfire is coming from.