Why would the MAF fuse blow?

[eLeSthree]

After extensive troubleshooting, I found that my MAF fuse (#14 underhood panel) had blown. With zero maf frequency, my tune defaulted to the Speed Density (vve table), and ran like crap. Im currently running a maf only tune.

I replaced the fuse and all is fine now, but why would it blow in the first place?

I was logging at the time it blew, and the maf was reading around 10,000hz, which is well within its threshold.

I ohmed out the maf side of the harness, and see nothing open. About the same resistance on all pins.

Im stumped. Any ideas?

[eLeSthree]

Originally Posted by eLeSthree

After extensive troubleshooting, I found that my MAF fuse (#14 underhood panel) had blown. With zero maf frequency, my tune defaulted to the Speed Density (vve table), and ran like crap. Im currently running a maf only tune.

I replaced the fuse and all is fine now, but why would it blow in the first place?

I was logging at the time it blew, and the maf was reading around 10,000hz, which is well within its threshold.

I ohmed out the maf side of the harness, and see nothing open. About the same resistance on all pins.

Im stumped. Any ideas?

Am I the first to blow a maf fuse??

[DSMer1]

I would be looking at the pins on the maf connector. That is weird that it blew

[eLeSthree]

Originally Posted by DSMer1

I would be looking at the pins on the maf connector. That is weird that it blew

I did take apart the maf harness connector, and I found the yellow wire's female connector was opened up to much. Possible that the male pin from the maf wasnt making good contact. However, I was under the impression that those last two wires, yellow and black, belong to the IAT sensor built inside of the maf sensor. Correct me if I am wrong there...

I squeezed the female connector closed so it makes good contact now. Picked up a few spare fuses, so I guess we'll see...

[DSMer1]

Correct, Pins D and E are for the iat. Are you using the iat in the maf?
Sorry for stating what I'm sure you already know, but I'm thinking outloud here...
The fuse popped because it was drawing to much load (power consumption) on the circuit.
At 10,000 hz it should be within the designed operating range of the circuit. What else could cause a excessive draw? I don't think anything else is powered by the same circuit but I don't have access to wiring diagrams right now.
I'm just trying to think this one out with you, I'm curious!

[eLeSthree]

Originally Posted by DSMer1

Correct, Pins D and E are for the iat. Are you using the iat in the maf?
Sorry for stating what I'm sure you already know, but I'm thinking outloud here...
The fuse popped because it was drawing to much load (power consumption) on the circuit.
At 10,000 hz it should be within the designed operating range of the circuit. What else could cause a excessive draw? I don't think anything else is powered by the same circuit but I don't have access to wiring diagrams right now.
I'm just trying to think this one out with you, I'm curious!

Yes, the IAT is in the stock location. It reads just fine on the VCM Scanner.

The first thing I looked for was a short somewhere in the harness. That is actually what lead me to the fuse box, where I saw the word MAF written on fuse #14.

I replaced the fuse, cleared the codes and drove the car hard for a few days. Seems to be fine.

I just found it odd that all my web searches came up empty. It's not a very common fuse to blow, and a blown fuse is a sign of a problem.

Here is the log from when the fuse blew. Start at 4:50. You can see where the MAF reads 10,XXX and then straight to 0hz. Throttle stays open but maf reads 0, it goes lean and hits fuel cutoff and slams the throttle closed. Thankfully.

[eLeSthree]

Cant upload hpt.log files here...

here's a screenshot of before.

[eLeSthree]

and just after...