View Full Version : Code 157 - MAFS

04-07-2003, 03:40 AM
I just finished replacing my valve cover today, which was bad. After I put everything together I started the car up. It started up better then ever, but it wouldn't idle. It just died.

I ran the codes and came up with Code 157 which is Mas Air Flow Sensor Fault: Low Voltage.

How do I go about correcting this problem?

Thanks a lot...

04-07-2003, 11:30 AM
I'd check the wires on the Maf to make sure they are good and tight and that you have no loose wires around.

04-07-2003, 03:42 PM
When I upclip the MAFS wiring from the sensor, the car starts. When I put it back on the car dies or doesn't start. So there for I know their is something wrong with the MAFS or the wiring. Where exactly does the wiring lead?

Also, I just got a new C&L and it has been fine for 2 weeks until yesterday when this happened... I'm sure it's a wire, but where do they lead, cause I can't find it.

04-07-2003, 04:11 PM
I don't have the pinpoint tests for your year to reference. But the MAF leads are going to go right to the ECC.

Describe further how the car doesn't start. Does it stumble and die, or does it idle for a moment and cut out? Do you smell fuel?

Disconnecting the wires could also mean that there is a problem in the MAF or in the intake, that causes the MAF to output invalid values. Too low would mean something like very low air flow. Has something blocked the inlet somewhere? Is the sample tube properly in place?

You might try swapping out MAF's if you still have your old one. When you disconnect the MAF, the EEC then ignores any readings from it and uses default values. So I guess I'd still be questioning the MAF or something that could impact the air flow through it.

04-07-2003, 09:44 PM
The first few times the car would go on and jump to 1000rpms and then drop down and die. It was about a 2 second event. The last time I tried it, it started the rpms jumped and to 1000 and dropped to 500 3 times before the car shut off.

04-07-2003, 10:52 PM
look at the elements they probably have something in them or the MAF is bad. Don't unplug and plug it in with the car running you could damage it. Basically it's trying to tell you there is no output from the MAF. A and B are power in and C and D are signal out. You could measure the voltage out at C & D.