B8 A4 - Help Needed! Dead Car

[XtremeXiong]

Hello all.

I was wondering if anyone would be able to help me figuring out what's wrong. I was driving around town and was caught at a stop light when my car completely shut off on me. After looking under the hood I found my MAF sensor disconnected and melted by the heat. Shouldn't the car still be able to turn on even without it plugged in (running rough)? It still will let the car go into accessory mode and the battery was just replaced 1 month ago. Any help is much appreciated.

[bakedziti]

Weren't you looking for the pins for the female connector for your MAF this week? If so, I have to ask what you did? Wires melt from shorts, but I don't think an automotive grade wire in the engine bay would just melt from heat.

[Project Quattro]

@lambda13 had his melt also. I don't recall whether or not the car ran, but it definitely messed up his ECU. Maybe he can chime in.


Sent from the Pedal Responce boardroom

[XtremeXiong]

Weren't you looking for the pins for the female connector for your MAF this week? If so, I have to ask what you did? Wires melt from shorts, but I don't think an automotive grade wire in the engine bay would just melt from heat.

Yes, I was looking for the pins for the female connector. I believe it was contacting the HFC or Turbo and the heat from either was melting the plug.

[van462]

The MAF gets gets its power from the ECU. The HFC is also a ground. When a MAF comes unclipped it lands on the cat or turbo. If the power feed melted and contacted the ground you may need to start checking fuses. Likely the ECU fuse is blown and why it won't run. With the MAF disconnected the car will idle perfectly fine, once you start applying throttle and it needs to read the changes in air volume it will sputter badly. The ECU should command the wastegate open to limit boost and possible overlean conditions.

[XtremeXiong]

The MAF gets gets its power from the ECU. The HFC is also a ground. When a MAF comes unclipped it lands on the cat or turbo. If the power feed melted and contacted the ground you may need to start checking fuses. Likely the ECU fuse is blown and why it won't run. With the MAF disconnected the car will idle perfectly fine, once you start applying throttle and it needs to read the changes in air volume it will sputter badly. The ECU should command the wastegate open to limit boost and possible overlean conditions.

@van462 Thanks for the information. I'll check the fuse and report back. Hopefully it is just the fuse and not the whole ECU.

[van462]

Make sure the pins aren't shorted to one another as well.

[Lambda13]

The MAF gets gets its power from the ECU. The HFC is also a ground. When a MAF comes unclipped it lands on the cat or turbo. If the power feed melted and contacted the ground you may need to start checking fuses. Likely the ECU fuse is blown and why it won't run. With the MAF disconnected the car will idle perfectly fine, once you start applying throttle and it needs to read the changes in air volume it will sputter badly. The ECU should command the wastegate open to limit boost and possible overlean conditions.

My MAF wasn't working for months and I didn't have sputtering, surprisingly.

[van462]

Any update on this, another member has a very similar issue.

[XtremeXiong]

Any update on this, another member has a very similar issue.

Hey! So I figured out the issue. When my MAF sensor came unplugged it grounded the MAF fuse when it got melted by the turbo. Replaced it and it fired back up!

[van462]

Thanks for the update, which fuse panel was it located in, driver/right dash, passenger/left dash or truck?

[boactionjaxon]

Hey! So I figured out the issue. When my MAF sensor came unplugged it grounded the MAF fuse when it got melted by the turbo. Replaced it and it fired back up!

Was it throwing any codes up on the dash?

[XtremeXiong]

Hey sorry guys for not responding sooner. The vehicle was throwing a MAF code only. And the fuse is located in the trunk.