1998 s70 MAF input too low

goVolvo · Post by **goVolvo** » 22 Jan 2015, 07:06

Hi, I got this code still persistent after MAF replaced. If I clear the code, start the engine, it shows up again when RPM goes down to normal in one second. Does it mean connection problem or vacuum leak? I also noticed that giving a little gas at idle, RPM will dip to 700 then go back up, very repeatable. Seems ECU detected something either too rich or lean, then counteracted? Driving is all right though. Maybe ECU uses default number anyway.

Anyway to measure the voltage on the pins through the harness to see if MAF output is normal?

goVolvo · Post by **goVolvo** » 22 Jan 2015, 07:16

Just found this video, very useful.

How to Test BOSCH MAF Sensor

goVolvo · Post by **goVolvo** » 22 Jan 2015, 20:59

Heck, there is no 12V on the MAF connector. Any fuse can cause this? ECU problem? The wire looks OK. Now need to study wiring diagram.

Post by **erikv11** » 22 Jan 2015, 23:12

Is the new MAF a Bosch? The various aftermarket brands usually don't work in these cars.

goVolvo · Post by **goVolvo** » 23 Jan 2015, 06:32

It is a refurbished BOSCH MAF insert I put in the BOSCH housing. But regardless, the 12v voltage should be there on pin 2 and 1, right?