Magazine for the auto service professional
Issue link: http://asp.epubxp.com/i/660061
Circle 110 on Reader Service Card better, you'll know for sure something is wrong with the MAF sensor. Always to turn the ignition switch off before connecting or disconnecting any sensor to avoid the possibility of sending a voltage spike to the PCM. Cleaning vs. replacement Most OEM service information will tell you a MAF cannot be cleaned. Sometimes this is true because the hot and cold wires (which look like tiny resistors) simply cannot be accessed. On some models, cleaning the sensor is only a temporary fx because the contamination is a result of potting mate- rial leaking out of the sensor assembly itself. But the best reason to replace a dirty MAF sensor rather than trying to clean it is to avoid a come-back. Even if you plan to replace the part, cleaning a MAF sensor is a good way to confrm your diagnosis before spending the customer's money. If the MAF is dirty enough the cause the driveability problem, even partial cleaning will restore some of the engine's performance. There are special chemicals available for cleaning a MAF sensor, but many techs are comfortable using any spray cleaner that dries quickly and doesn't leave a residue. Simply spray it on and let the chemi- cal and dissolved dirt drip away from the sensor. The job requires a gentle touch and practiced technique to avoid damaging the fragile wires. Do not use compressed air, and do not install the sensor until it is completely dry. The best part about cleaning or replac- ing a MAF sensor is the immediate and sometimes dramatic improvement in engine performance. The engine will run better, and that will help your customer feel better about the cost of the repair. And, of course, knowing you fxed it always feels good, even if some- times it really is this easy. ● Powerplant