I've got a 2006 MCS-GP that has ~90K on it and has recently decided not to start.

Yesterday I drove the car into work on a rainy day, and the Tire and DSC warning lights came on. I'd seen this happen before, only when it's been wet out, and was told that it was the stability Control module causing an issue. When it dries up, the problem goes away. Been this way since last year and living in Northern California where it rarely rains, I just ignored it.

So I arrive at work, the warning lights are still on, but I'd seen this before and it wasn't a big deal.

After sitting all day in the parking lot, I come out and sit in the car and notice a sharp "burning electronics" smell within the cabin of the car and the car won't start. All the normal lights come on with the key and it cranks when I try to start it, but never makes an attempt to start. I pop the hood and sniff around, but don't smell any of the same burnt electronics smell under the hood. It's only in the cabin of the car.

This morning I come in and connect a code reader to the ODBII port, and get a P1498. I tried clearing the code but got no change. (not that I'd think clearing a code would fix something that was burnt.)

Anyone know what this might be? I can't seem to pinpoint the smell within the cabin. Any suggestions on what to look at to determine the burning smell source? Can someone tell me where the Stability control module is located so I can check that?

Thanks!

Greg

 

Check the drive belt and the crank pulley. They start to smell like burning rubber when they go.

 

That would require the car to run, which this does not. Also, the smell is strong inside the cabin and nonexistent under the hood. Thanks for the suggestion though!

 

Check all connections to your battery and terminals.

Also your P1498 is (Unmetered air after compressor) Check for leaks in the intercooler or the tube that goes from the back of the SC to the TB.

 

Your code is an Auxiliary Emissions Control problem...
But I honestly don't know about that smell... maybe an electrical short under the steering?

 

Checked the battery terminals and connections. Everything was solid and no smell was noticed inside the battery compartment.

I'm guessing the P1498 is a separate problem from the electrical burning/fail to start question, perhaps?

Thanks!

Greg

 

It's definitely not related to the burning smell indeed,
I strongly suggest that you open under the steering wheel and maybe behind the radio to look for a short between cables

 

Great. Thanks for the advice. I'll open it up and let you know what I find.

-Greg

 

I tend to agree with Braminator. A gross intake leak would inhibit starting if sufficiently large such that the ECU couldn't adapt. Check both IC boots closely. I once removed the IC to install spark plugs and failed to install one IC boot properly. Got a similar smell but no damage and rectified my mistake w/o any subsequent problems.

 

Consider pulling fuses and relays for the auxiliary circuits, radio, wipers, heaters, lights etc, especially those with non-BMW equipment on them.

Inspect each fuse using a multimeter (not by eye). The car should start and run (although it may light up like a Christmas tree) with most fuses out except the engine/fuel type ones.

Be sure to note the number of fuses and the values that differ from the fuse map, to make sure you can reassemble.

Disconnect the battery when mucking about at the fuse box as there are many permanent live circuits there.

 

I opened up the steering column and didn't see anything obviously burnt or disconnected. I'll go down the fuse panel route and see what I get. Thanks for the continued advice.

Greg

 

I went through the fuse boxes (both the one in the driver's kick panel and the one under the hood) and found no fuses that didn't ohm out correctly.

One thing Ive noticed that over the past few days I've been poking at this thing, on the first attempt to start it seems to catch briefly, then just crank, as if it got a burst of fuel for a second (or pressure had built up ) but then won't catch again until I let the car sit overnight. Could this be a fuel delivery problem? Wouldn't the code reader tell me if there was a fuel delivery problem?

Any ideas or thoughts appreciated.

Greg

 

Since you smelled burning electronics I would suspect a short somewhere.
However, you can check the basics:
Do you have fuel pressure at the fuel rail?
Do you have adequate spark at the spark plugs?
Are the coil to spark plug wire connections in good shape (no corrosion)?
Are the spark plug wires in good shape and good connection at plugs?
Are the spark plugs in good condition?
Has the crank pulley separated?
Is the crank position sensor wire in good shape and connected to the sensor?
Are the brake/clutch lock-out switches working properly?

 

Is the fuel pump running? Is the fuel filter breaking up? It the fuel pump voltage good even during cranking?

 

So here's the winner:

Turns out to have been a bad fuel pump relay.

I first checked the fuel pressure at the fuel rail, by pressing in on the Schrader valve. Nothing really came out save a small drip, which means I had no fuel. I checked the fuse for the fuel pump, which seemed fine, so i went ahead and ordered a new fuel pump. I installed the new fuel pump and excitedly gave it a try, and nope: Still won't start.

I then decided to check out the fuel pump relay to make sure it's getting power. After removing the kick panel, I removed the two nuts that held on the fuse box, and I could tell I found my problem. The plastic housing around the fuse box showed signs of burning. I disconnected the fuse box from the harness, removed all of the fuses and opened up the fuse box housing to find the fuel pump relay had completely burned up, trashing the board underneath. Shouldn't this have been protected by a fuse? $75.00 off ebay got me a new fuse block, and the car started no problem.

Now to get that burning electronics smell out of my car.

 

Do you have any after market holes in your firewall or holes on your floorboards? Seems like water build up every time it rains like you said... Next step... Stop repairing the symptoms and find that leak!!

We ALMOST had rain today here in NorCal... I'm Bay area. I got a little drizzle in Livermore. Ha.