Cascade Crew

[nonsensekid20]

Alright here goes, I have a 98 nissan altima with 246846 miles and every so often the check engine light comes on and pulls the code P0100 MAF or VOF or something like that. The light only comes on after the car does a horrid lurching or loses power. It doesn't stall, just loses power. The MAF has been replaced and the problem still persisted. I've looked around and people have said check electrical connections, vacuum lines etc. Just wanted to see if anyone else may have had this problem elsewhere and fixed it. Thanks!

[Twilightoptics]

MAF's are bad for those cars.

1. Check for battery voltage to the MAF sensor on the White/Red wire with the key on.

2. Check for a good ground for the MAF sensor on the Black/Red wire - look for 0.05 volts or less.

3. Check the MAF sensor output voltage on the Brown wire - look for about 0.5 volts key on engine off and about 1.2 - 1.5 volts at warm idle.

4. Verify the MAF sensor output voltage on the Brown wire at terminal 47 of the Engine Control Module (ECM) as necessary.

5. Check the MAF sensor grams/second - specification is approximately 3.24 grams at warm idle and approximately 12.2 grams/second at 2500 RPM no load.

6. Check the calculated load - specification is approximately 19% at warm idle.



If there is a symptom before it triggers the CEL with that code, the maf probably has nothing to do with it. Example: Sometimes O2 sensors codes come up when spark plugs aren't doing their job, because the combustion isn't what it should be, so the O2 reads out of range.



1998 Altima 2.4

Customer Concern: Malfunction Indicator Light (MIL) is ON. Mass Air Flow Sensor code P0100. Intermittently bucks and hesitates. Running fine right now.
Average Reported Mileage: 104987
Tests/Procedures: 1. Check freeze frame data first to see what the parameters were when the code set. See if any of the freeze frame data can give and indication of what happened when the code set. See if the Mass Air Flow Sensor voltage is displayed or calculated load or Mass Air Flow Sensor grams/second. See what the fuel trims read, etc.

2. Check for battery voltage to the Mass Air Flow Sensor on the White/Red wire with the key on.

3. Check for a good ground for the Mass Air Flow Sensor on the Black/Red wire - look for 0.05 volts or less.

4. Check the Mass Air Flow Sensor output voltage on the Brown wire - look for about 0.53 volts key on engine off and about 1.38 volts at warm idle.

5. Check the Brown signal wire for possibly intermittently grounding into the shield.

6. Try tapping on the Mass Air Flow Sensor and wiggle the Mass Air Flow Sensor connector etc while monitoring the signal voltage on the Brown wire and see if the voltage changes.

7. Verify the Mass Air Flow Sensor output voltage on the Brown wire at terminal 47 of the Engine Control Module (ECM) as necessary.

8. Check the Mass Air Flow Sensor grams/second - specification is approximately 3.24 grams at warm idle and approximately 12.2 grams/second at 2500 RPM no load.

9. Check the calculated load - specification is approximately 19% at warm idle.