MAFT troubleshooting: no maf signal

[Echo5Zulu]

Helping a friend of mine diagnose and fix a problem with his GM maf translator. The unit is getting power but it is giving us the double red blinking light wich indicates no maf signal. We checked the harnesses and they look fine. No broken wires or plugs.

Does anyone know what voltage signal should be coming from the maf so I can check it with a meter? I read another post during my initial search and someone mentioned there should be a 0-5 volt signal comming through, is this correct? Is there another way to check the maf?

Also the car barely idles because its soo rich. My guess is that it is in ECU limp mode since its not getting signals from the maf or the translator. Changing the dials on the translator doesnt make a difference. The red light will blink once to indicate its accepted but nothing happens. The only way to get it to run is to drop the fuel pressure down to like 20lbs or something silly low. Thanks.

 

[Echo5Zulu]

Anyone know a good way to test that gm maf? Can I just test for a 0-5 volt signal while its running?

 

[talonalex92]

test the maf w/ the car running by TAPPING on it with a hammer or screw driver and if the car stalls or stumbles bad its no good.
do you have the maf hooked up into the right and correct wire on the CAS

 

[Echo5Zulu]

test the maf w/ the car running by TAPPING on it with a hammer or screw driver and if the car stalls or stumbles bad its no good.
do you have the maf hooked up into the right and correct wire on the CAS

Thanks for the tip, but I dont know if it will work since the maf translator is allready saying its not getting a signal from the maf. We'll try it though.

 

[Echo5Zulu]

Update: We ended up checking all the wires in the maf plug by running current through them at one end and checking at the other. Ended up finding a bad connection in the wire from the maf to the harness in the car. Someone accidently created a cold solder weld that only yeilded an intermittent signal. So we replaced that connection, and retested. Unfortunatly his battery died on us so we had to put it on the charger, and wasnt able to test it by running the car. Hopefully she'll be set to tune once its charged.

 

[Echo5Zulu]

Still wont run. Still no signal from the maf. Also tried hooking up a diagnosis computer and arent getting a maf signal. Pulled the maf and tested it with an ohm meter. Tried it cold then tried it warmed up with a hair dryer but no change. Does this mean its fried? Is it possible that he plugged the maf or the translator in backwards and fried it when he turned on the car? The problem occured right after he moved things around and unplugged then replugged it all back in. Anyone with maf experience please chime in as we arent getting too much help so far. Thanks.

 

[talonalex92]

you could try using someone elses translator if accessable, or a new gm maf perhaps..

 

[KPEclipse]

its like you're having the nightmare I already had...

I switched mine to blothru with the GM MAS and MAFt, NEVER got a signal...sent my MAFt out for repair, tested the MAS, the whole 9, kept getting a CEL, so I ended up saying screw it...

we tested it the same way, and mine was functional, but the car kept throwin CEL for no MAS. ended up sayin screw it, and now I'm doin 2g MAS.

I was told that its very sensitive to where the MAF is placed in the piping, that could throw it, or, well it could be a plethora of things. Check to make sure the MAS is sending signal, then check the yellow wire to see if the MAFt is sending signal to the ECU. That's all I can, and could think of, which is why im on 2g MAS now. Too bad my car still isnt running(bad ECU)

 

[KPEclipse]

well not just a bad ECU, bad socket job for my chip.

 

[Echo5Zulu]

We're pretty sure the maf is dead since we tested it for voltage in the car and got nothing and we tested it for an ohm change out of the car to no avail. It ran perfectly until he unplugged it and moved it. I think he may have plugged it in backwards and fried it, is this possible??? We're going to pick up a new one and give it a shot. I'll post the results afterwards. Thanks for the suggestions.

 

[KPEclipse]

Yeah mine did the same thing, as soon as I unplugged it, moved the MAS, and plugged it back in, started acting up...post your findings and if you really things its a bad MAFt and need a new one, I have freshly refurbished unit straight from fullthrottle.