Desired range 11.7-12.6? 11.7V would be a dead battery and fully charged would be 12.6V. I think the reason he had to charge it is because he has been cranking on his car trying to get it to start, which in turn drained the battery. Below is a chart with the open-circuit voltage with its corresponding charge. Hope this clears up any confusion.


12.66 V 100%
12.35 V 75%
12.10 V 50%
11.95 V 25%
11.70 V 0%

 

Here are the list that I'm positive about:

1.) Battery is new and I only have 1 under the seat. No other battery in the trunk.
2.) When trying to start, I get no crank. New Battery is 12.4-12.9 when I try to start the cayenne.
3.) I checked the ground under the seat and it seems to be connected fine.

I'm pretty sure I have fuel because before it started to sputter on the highway, I filled it up at a Shell gas station (91). Then about 20 minutes later the car sputtered and died.

Will a bad fuel pump prevent the cayenne from cranking? As you can see from the video (link below) when I try to start, lights on dash goes off and no crank.

Here is a quick video.

https://www.youtube.com/watch?v=h0zs...ature=youtu.be

 

I assume your depressing the brake pedal, and car is fully engaged into park position when trying to start ? Sorry to ask the obvious, but when I get perplexed I forget the obvious....lol

Could it be the DME ?

Simple as ignition control unit ?
http://www.6speedonline.com/forums/c...ont-start.html

Hoping, this ends as a simple fix....

 

Yes I am.

I've had the Cayenne since 2009. We love it and now can't stand not being able to use it.

 

Are you checking the battery with a volt meter? If so, with the ground disconnected what is the battery voltage?

When turning the key to try and start is the steering wheel still locked in position (theft deterrent)? In other words with the key in the accessory position is the steering wheel still locked?

 

I just went and checked the battery with ground disconnected and it's at 12.4v.

When I put the key in, I feel the steering wheel unlocks itself and I'm able to turn the steering wheel left or right. If I remove the key, the steering wheel locks and I can't turn it.

 

If it doesn't crank but your batter has good voltage, then it's not the battery. It's probably a starter if you get no "Click" sound or anything. Either that or a connection along the important path of electricity for starting has come undone. There's a few important connections. Battery to Starter, Batter to Alternator, and Engine to Chassis ground. Check those. It's 110% not your fuel pump. Your car would still crank with a bad fuel pump.

 

Desired wasn't the right range, workable was. Anything above 11.7 and your car has the capability to start. Even with reduced voltage enough amperage will turn your starter. This is all dependent on temp too, but basically if your battery reads 12.xx anything then you're good to go. Each battery varies from the factory anyways, IE: 12.66 isn't 100% voltage for every battery due to physical limitations. Mathematically perhaps, but not post production. 12.2v and higher and you're good to go.

 

You're forgetting that the ECU starts the car, not the key. You turning the key doesn't do anything except tell the ECU to start the car. Battery voltage, connections, it's all meaningless if the ECU is throwing a fault or doesn't believe you have the right parameters to start the car.

The car suddenly sputtering and dying, then cranking but not starting doesn't sound like a dead battery issue. For sure, you're overdue, but all those faults when you turn the key are showing up for a reason. Typically, the car throws a billion weird, unrelated codes when the battery starts to go, and that will happen well before the car fails to run. You also should have been shown a battery error on your screen before your car died. If the battery was the issue, then many of those codes should have stayed off when you turned the key on. They'll be stored, but not active.

Have you checked all the other fuses, like the ECU? Pull each fuse one by one to ensure you don't have something odd blown. When you open the door after the car has sat for awhile, do you hear the fuel pump turn on? Usually, when you unlock the car and open the door, the ECU triggers the fuel pump to come on (you should hear it buzz briefly) so you have full pressure before cranking. I don't think you have a fuel pressure problem, but whether or not the ECU is turning it on briefly might help point to whether or not it's functioning properly.

If all the fuses are good, I would really find a way to scan those codes before going any further. A battery so dead the ECU won't turn over the car should throw the battery indicator on your screen.

 

Yeah, those are the two places I would look. A fuel pressure problem would still result in the car turning over. But a "no start" compared to a "failed start" would make me look elsewhere than the battery. There are only a handful of sensors and modules that will prevent the motor from turning over and running.

 

If you go to crank (and no cranking happens) and everything loses power including dash lights and the battery itself is OK, you have a high tension wiring problem: the connectors on the battery are loose or corroded so the connection is poor not permitting enough current draw when the starter tries to engage. If your connectors to the battery are OK, then you need to track the connection of the heavy gauge + wire from the battery to the starter - somewhere it's damaged or loosely connected so you can't draw enough current when it's needed. A bad connection would permit low current draw like dash lights... First thing I'd do is remove the driver's seat, clean and re-seat the terminal connectors, then try to start the truck again.

 

Profusion,

Stop flailing. Start checking a few things. Battery voltage at 12.4-12.9V is OK (12.4 isn't fully charged but it's charged enough.)

Check the battery voltage when trying to start the vehicle. If it drops down to 11V or so - the battery is not fully charged, or has an internal fault (cracked conductor). Replace the battery.

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If that isn't the case - and the voltage stays good at the battery when trying to start the truck, move on to the next check:

Check the battery voltage at the jumper post under the hood (located under the plastic beauty panel under a little door) with the positive lead on the post and the negative lead on the engine. If the voltage is different from what you measured at the battery itself you have a wiring problem. Chances are the ground cable from the battery - which goes to the chassis right in front of the drivers seat - is loose or corroded.

If the voltage appears the same at the jumper post - keep the voltmeter connected while someone else tries to start the car. If the voltage drops considerably (like less than 12V) - you have a wiring or ground problem. See above for where to start to look.

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If the voltage stays the same at the jumper position - it's time to hook up a Durametric and see what's happening. Look for the system voltage (on a BMW it's always called "Terminal 15" for some reason..) See if there are low voltage faults reported, or any modules not responding or turning on.

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For whoever it was who suggested charging a new battery before installing it is a bad thing, you are absolutely wrong. It's recommended on ANY wet-cell battery that it be fully charged before installing it in the vehicle. Wet cell batteries have a memory factor where if they're put into use before being fully charged they will never reach full capacity as they're being used.

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Profusion - try the measurements above. Report back. It may be the problem is beyond your capabilities in which case it makes sense to bring in a professional.

BTW - Garrett - very close, but the fault would be a high-resistance fault, not a "high-tension" fault (I have no idea what that would be..)

 

Any resolution!?

 

Got it... "high tension" is high voltage like spark plug wires... I was typing faster than thinking...

 

If y'all drive drive expensive cars and want insurance for moments like this above, y'all need to look into AAA Plus. For a little over $100 per year for two people and your cars, AAA offers flat bed trailering to the shop of your choice for free, up to 100 miles. It's a good deal and I have used it a number of times. With that coverage, AAA also offers free starting, fuel, and locksmith services, should you ever need those (which I have, several times). And AAA's travel services and travel discounts are worthwhile too. My wife and I have been members for many years. Check it out...