worst case for "!" light on 90 C4? got a long trip

[Nate911]

First off - long time lurker, first post. These forums kick ass.

Got a buddy looking to pick up a 90 C4 cab for a project. It's got a known history of body damage, an oil leak, and he's getting it for what amounts to wholesale or less. Little history available on the car, but we're not looking a gift horse in the mouth.

That said, he needs to drive it 2 hours before we can have it fully checked out. It seems to run and drive well, BUT the "!" light is on. It can be switched off with the switch on the lower center console, but comes back on when restarted.

Anything crucial we can check before the trip to minimize chances of a break down? I know little about (but have always admired) the 964 series cars...I figure there are so many things potentially tied to the "!" light that perhaps we just need to grit our teeth and drive. Maybe the list is shorter than I think, and includes things we can check? Fluid levels associated with the AWD system or something? NG

[Don Plumley]

It could be something trivial, or something big - do all of the other idiot lights illuminate when you turn the key to pos II?

There's a way to read the OBD I codes with the brake pedal or something IIRC - if you don't have access to a Hammer. If I have time I'll try to search for you...

[rattlsnak]

isnt this normal?? on every 964 ive seen, it comes on every time you start it and the button must be pressed? anybody else?

[Nate911]

Originally Posted by rattlsnak

isnt this normal?? on every 964 ive seen, it comes on every time you start it and the button must be pressed? anybody else?

That would be fantastic news - if it's the case, I apologize for my ignorance of these models, I've only had my SC and a mid year.

[911JC911]

Originally Posted by rattlsnak

isnt this normal?? on every 964 ive seen, it comes on every time you start it and the button must be pressed? anybody else?

Nope. Mine goes off by itself. The spoiler light goes off when you start moving.

[Nate911]

Does anyone have a link to a comprehensive list of items the warning light monitors? And what can we check aside from oil?

[Shack2112]

My ! also goes off after a few minutes. Along with 911CJ911 my spoiler light will at times stay on until the car starts moving.

John
1990 964 C4 aka "Baby"

[crg53]

It will come on for just about anything, including a simple thing like low on fuel.

[jasonmx5]

All of the above. "!" light will come on for low fuel, spoiler not deploying, emergency brake on, low oil pressure, etc. All of these should be accompanied by the appropriate warning light - the "!" is just an alert. Sort of like the envelope down by the clock if you use windows and outlook - it tells you that you have mail, but not what's in it, or who it's from.

The light should go out automagically when the appropriate sensor triggering the light has been satisfied - if not, you may have bigger problems. In the case of the "spoiler" light, from what I understand, there is a speed sensor that leaves the light on at start up until you move above 5 mph. This is so that the computer knows that the speed sensor is working properly, and it then extinguishes the "spoiler" idiot light and should put out the "!" as well. Other than that, the "Spoiler" light should only trigger when you are travelling over ~50 mph and the spoiler fails to rise, which could cause an overheating situation.

[jasonmx5]

Slight correction to my previous post. The "!" light stays on for 5-10 seconds until the last warning light goes off - typically the airbag light, but the "spoiler light stays on until you move above 5 PMH. Just went for a ride to test the theory

[rattlsnak]

hmm, i have always just pushed the button, and have never waited to start moving or waited to see if it went out on its own..

[Don Settergren]

The fault light means that something is not right if it stays on past the initial test cycle upon startup. Check the fault code by following some intructions I grabbed from Rennlist for reading the code without the Bosch Hammer (thanks 95C4VanIsle - Bret)

"I learned here that in the MY95s, you can check the CEL codes without an OBD reader. If you turn the ignition on and hold the gas pedal to the floor for three seconds (and don't turn the car on) and wait for the CEL to flash and then take your foot off the gas you can read out the fault codes. The CEL will flash out fault codes almost like morse code. If there are no faults the CEL will flash once then pause and then flash 5 more times.

You should have a single flash then a pause, then a single or a double flash. If the flash is double then the fault is intermittent (loose contact) otherwise the fault is constant. And then the following flashes;

11 Supply voltage
14 Engine temp sensor 2
15 Throttle potentiometer
18 Rpm signal
19 Speed signal <- Speedometer
21 Hot Film Mass Air flow sensor
22 Oxygen Sensor (Signal)
23 Oxygen regulation
24 Oxygen sensor
25 Intake Temperature Sensor
26 Ignition timing change
27 Opening winding of idle stabilizer
28 Closing winding of idle stabilizer
31 Knock sensor 1
32 Knock sensor 2
33 Control unit faulty
34 Hall signal
36 Idle CO potentiometer
41 Control unit faulty
42 Fuel pump relay (DME-relay)
43 Tank ventilation relay
44 Air Pump
45 Check Engine warning lamp
51 Injection valve cylinder 1
52 Injection valve cylinder 6
53 Injection valve cylinder 2
54 Injection valve cylinder 4
55 Injection valve cylinder 3
56 Injection valve cylinder 5
67 Ground and plug connections
69 Ground and plug connections

[kylejohnston1]

Please forgive the rookie question, but what does MY95s stand for?

Thanks,

Kyle

[Don Settergren]

95C4VanIsle explains that these codes can be pulled from 1995 911 cars, so MY95s = Manufacture Year 1995 (plural).

[rbogh901]

Don or anyone? Good info.

Does this same technique apply for 964's?

[Oracle]

Yes as of 92 or 93, for earlier models it must be "California" designated cause it was the only one that needed it to comply, in summary Porsche had 2 DME for USA Cali and non-Cali.

[rbogh901]

Oh, then my '91, and your '90 will not read out codes without a Hammer then? I doubt my car is a Calif car. When issues come up I'll have to find someone with the Bosch. While codes are listed their retrieval is not explicit in the Streather book.

[rbogh901]

more info from Rennlist's Bill Wagner:

"It seems to me that 1991 appears to be a changeover year, meaning that sometime in the 1991 production run the DMEs were changed (US only by the way) so that the diagnostic capability became useful. Some California cars had this feature enabled as well before it became a standard feature... Please keep in mind that for the most part the active Check Engine Light applies to 1991 and greater US MODELS ONLY"

http://members.rennlist.com/billwagner/CheckEngine.html

Quite helpful info.