Cayenne 1117 & 1494 codes - any help or advice would be appreciate

[EMC2]

Vehicle = Cayenne S 2009. TipTronic (957)

 

My Wife was driving the car today, and whilst she was parking (shifted from Drive into Reverse) the engine stalled. This has never happened before.

 

She says a headlight warning came up at the same time.

She was able to start the car again immediately without any problem.

 

The car drove afterwards without any problem.

When she got home I plugged in the Durametric and got the following Faults:

 

"1117: Load Signal Generator Terminal DF - Implausible Signal, test conditions are not completed, fault is currently active and is not causing a DTC light"

 

"1494: Parking Light Left - Open Circuit, test conditions are not completed, fault is not currently active and is not causing a DTC light"

 

I tried to clear the faults, but they would not clear.

I also checked all front and rear lights on the vehicle and all function correctly.

 

I measured the actual values of the voltages of the car and got the following using Durametric:

 

"Voltage of vehicle electrical system":

hovering between 13.2V and 13.25V at idle, and

went up to 13.3V at a steady 2k RPM

 

"Generator Setpoint Voltage"

14.3V at idle and

14.3V at a steady 2k RPM, and

10.6V with engine off and ignition on.

 

I drove the car for about 15 miles at varying speeds and there is absolutely nothing wrong with the idle or the way it runs. As strong and smooth as ever.

 

However I am very concerned that this 1117 fault is currently still active.

 

I spent a lot of time searching and the following is one thread that I found interesting:

http://wiki.ross-tech.com/wiki/index.php/01117

 

What I don't understand is the connection between the parking light code and the Load Signal Generator code, and how either could have caused an engine stall.

 

Any tips or advice would be most appreciated.

Thanks in advance.

[EMC2]

Would a momentary short in the light wiring cause such an error? (just speculating)

[Loren]

How old is your battery? If it is 4 plus years old I would replace it.

Cayenne's do some pretty strange stuff when the battery is weak.

[EMC2]

How old is your battery? If it is 4 plus years old I would replace it.

Cayenne's do some pretty strange stuff when the battery is weak.

Thanks Loren - I should have stated that the battery was already replaced 18 months ago.

I also disconnected and reconnected the battery, but am still unable to clear the 2 codes.

Edit - with ignition, lights aircon & radio on (but engine off) I get just over 12V reading on the dash

Edited August 31, 2015 by EMC2

[Loren]

1494 Parking light bulb, left

 

Possible causes:

- 'Short circuit to B+' Continuous lighting of side light bulb(s) can only be diagnosed when side light is switched off .

- 'Short circuit to ground' Failure of side light bulb(s) can only be diagnosed when side light is switched on, fuse may be faulty

- 'Open circuit/short circuit to B+' Continuous lighting of bulb(s) in the event of a'short circuit to B+', can only be diagnosed when side light is switched on.

- 'Open circuit/short circuit to B+' No lighting of bulb(s) in the event of a'disconnection', can only be diagnosed when side light is switched on

 

A direct short could cause the 1117 fault but best check the alternator connections (battery disconnected) also.

[EMC2]

Thanks Loren: my comments and questions below in Bold Red (note I changed the sequence of points):

 

Possible causes:

- 'Short circuit to B+' Continuous lighting of side light bulb(s) can only be diagnosed when side light is switched off .

Short not active as parking light turns on and off correctly as expected - tested using both sides independant parking light  function also

 

- 'Short circuit to ground' Failure of side light bulb(s) can only be diagnosed when side light is switched on, fuse may be faulty. 

Short not active as parking light turns on and off correctly as expected - tested using both sides independant parking light  function also (will check fuse now)

 

- 'Open circuit/short circuit to B+' No lighting of bulb(s) in the event of a'disconnection', can only be diagnosed when side light is switched on 

If I understand this correctly, it would show as a bulb not lighting when intentionally switched on?

 

- 'Open circuit/short circuit to B+' Continuous lighting of bulb(s) in the event of a'short circuit to B+', can only be diagnosed when side light is switched on.

Which points should I be checking between for this condition (B+ & ?)

 

thanks

[Loren]

B+ is the Black wire coming off the alternator.

This is the main power for the start and the other electrical circuits.

So check your alternator and starter connections as well as your chassis grounds.

[EMC2]

B+ is the Black wire coming off the alternator.

This is the main power for the start and the other electrical circuits.

So check your alternator and starter connections as well as your chassis grounds.

 

Thanks Loren. One more quick (and potentially optimistic :) ) question if you don't mind:

Is it possible to test the B+ without removing the alternator (i.e. tapping in further up the wiring)?

[Loren]

I guess you could disconnect the wire from the alternator (battery disconnected) and then check the resistance of the the B+ wire to chassis ground.

If the resistance is low you have a bad short somewhere.

 

Any third party add-ons or other electrical changes that might have caused this?

[EMC2]

I guess you could disconnect the wire from the alternator (battery disconnected) and then check the resistance of the the B+ wire to chassis ground.

If the resistance is low you have a bad short somewhere.

 

Any third party add-ons or other electrical changes that might have caused this?

 

Thanks Loren. No 3rd party add ons. 

I checked all the fuses and no problems there.

 

I haven't had a chance to get to the battery yet but I ran another durametric scan.

 

Very interestingly the 1117 code is still there but it now states that the fault is NOT currently active, whereas yesterday it was showing as active. The 1494 code remains there and is unchanged in the description also (i.e. still NOT  active).

 

Both fault codes (1117 and 1494)  still will not clear. 

I also ran an output test with the durametric to independently test all circuits on the vehicle electrical system and every step (including all lights) passed without a glitch.

 

I am now also wondering if there is an issue with Durametric not being able to clear these codes despite the fact that the faults are not active?

 

As soon as the car is back I'll be checking for any short via the battery terminals.

More to follow...

Edited September 1, 2015 by EMC2

[EMC2]

Quick update.

 

I could not detect any shorts from the battery terminals to Ground.

 

I also took the battery to get tested and it checked out fine. 

 

The only remaining code on the car is 1117 and the description still says Fault NOT currently active.

 

I called Durametric and they explained that often these kinds of codes cannot be "force" cleared and that the vehicle needs to go through a specific drive cycle before the system clears itself of any codes.

 

I was familiar with this type of scenario for Emissions testing from other Porsche's when the car can have  a "NOT READY" status and has to be driven up to 100 miles before being ready and compliant for an emissions test.

 

Whilst I hope this was just a one off event and the fault will clear itself, my next steps tomorrow will be:

1) check for any abnormal AC Voltage at the battery terminals (to determine if there is a diode issue in the alternator)

2) perform a parasitic current drain test as a precautionary measure 

[EMC2]

A quick update. 

 

There appears to be no parasitic drain occurring on the battery.

All electrical Fault codes are now cleared after a week of driving, however:

 

When I run a Durametric scan I get the red exclamation symbol under Vehicle Electrical System (part no. 7L.593.704.9A) , but no fault codes are present.

I'm going to give it another week and see if that clears by itself also.

 

Apart from that one strange event a week ago, the car has been operating flawlessly. A mystery indeed...

Edited September 7, 2015 by EMC2

[wvicary]

The only thing I'd like to add is in regards to the engine stall, have you cleaned the throttle body and reset the throttle body adaption after a cleaning? 

[EMC2]

The only thing I'd like to add is in regards to the engine stall, have you cleaned the throttle body and reset the throttle body adaption after a cleaning? 

Thanks - this is a good point also - I had cleaned the throttle body and MAF about a year back, just for maintenance purposes. All was good there.

I think this issue was definitely an electrical "glitch"

Edited October 5, 2015 by EMC2

[EMC2]

Loren - a 1 month update:

 

Car has been running perfectly.

I checked with Durametric again yesterday and there are no fault codes active.

 

the only thing that remains is what I said in post 12:

 

"red exclamation symbol under Vehicle Electrical System (part no. 7L.593.704.9A) , but no fault codes are present."

 

I'll run another scan in a couple of weeks and update the thread again.

[Doug_B_928]

The entire time I've had my Cayenne I get a phantom fault in the electrical system using my Durametric.  PIWIS does not show any faults.  I informed Durametric of this but they have yet to fix it.  I realize that you had a problem and so this fault could be legitimate, but just wanted you to know that this is an issue, at least with my 957S.

[EMC2]

Hi Doug

Thanks for the reply. Did your phantom fault have a code or only the red exclamation symbol?

[Doug_B_928]

Only the red exclamation. 

[Doug_B_928]

Here's a snip of what Durametric shows:

 

 

[EMC2]

Here's a snip of what Durametric shows:

 

Very interesting - thanks for the follow up Doug.

That's precisely what my Durametric scan shows as well.