andrewjn

I only have one working key fob for my 993 C4 cab. Bought a new one but come to realize the immobilizer warning light won't come on. Obviously this is a problem for programming the new key fob. I've already changed the bulb in the clock. I could swear that the light WAS coming on when i changed the bulb out but now it is out again. Took the car to my indy and there is no power coming to that particular light. The drive block and alarm works fine.

Any ideas on what could be causing this problem? The control unit immobilizer replacement is $1130 which frankly is too much in order to have a second key fob. I'm hoping this isn't the problem but this is what my indy has suggested may be the solution. Has anyone else experienced this problem?

nine9six

Yes, there is a strong possibility you have a ground fault in one or several locations within the circuit.

Check the following...
Micro switches at the doors, engine decklid, trunk, glove box, clutch pedal.

Also on that circuit are the inside lights, glove box light, trunk light an engine bay light.

If I missed any, hopefully someone else will chime in and add to this list.

I traced mine to a chafed wire to the light in the trunk.

andrewjn

Nine all of those things seem to be working fine. Funny though....the LAST bulb i changed out to LED was the glove box. It was working fine with the incandescent light. I took the light out and placed an LED and no go. Tried another brand LED and still nothing. Tried to replace back to the incandescent and now it isn't working either! Any ideas on that one?

ToreB

The clock instrument is known for its corroding connector, causing intermittent contact. You could try to disconnect/connect the connector several times to try to remove corrosion on the pins. Be very careful using any oil or contact cleaner, it could leak into the instrument. Sometimes the solderings/crimpings of the pins to the PCB lets go, causing intermittent contact. This can be corrected with some soldering iron skills.

The light bulb output in the Porsche Drive Block control unit might be shot, this is a more involving job. You could try to find out if there's any signal coming out of the control unit using a voltmeter. The unit is placed under the driver's seat, and most 993's have a anti-tampering metal shield over the engine and Drive Block units.
Cheers,
Tore

nine9six

That could very well be the issue...

It could be the GB micro switch that is out of adjustment or has gone bad.

Why not rectify the non-working glove box light and see if you don't have the immobilizer light operable in your clock.

pp000830

Solder connections in the clock are a known failure item. Take the clock out release the board by heatin the solder to the clock motor. Reheat all the solder connections and clean the bulb contact points. Reinstall the board and check and bend any of the bulb contact points as needed. An easy kitchen table job that will rule out the clock as the offending component.
Andy

andrewjn

911m5

I had a similar issue last year with no lights (immobilizer and glove box). As it turns out, changing the fuse (not sure if its #11) was the issue for me and a quick fix.

andrewjn

dacatz

Hi guys,

I have the same situation as well. Basically I have the pick up 95 c2 cab last September, the previous owner lost the fob, I have purchase new fob and i can't program the remote fob due to immobilizer light is not turning on at all. I noticed that there is a problem wire in the ash tray light. Do you guys think if that broke wire will cause the immobilizer light turn off? But i have tested alarm system, it is working. Any idea?

thanks,
Felix

LionelB

Bringing this one back from the dead. I have the exact same issue as the OP and ordered another key fob just to find out that the immobilizer light never comes on. I thought it was a broken bulb. So I took out the clock and at the location of the immobilizer light I have this white plastic thing. I am wondering what this is. Car is a 1995. Should I jut go ahead and remove this plastic tab and replace it by a bulb ? Thanks.

ToreB

The early 993's do not have a immobilizer warning light. I believe there's separate key fob programming instructions for the early types.

Cheers,
Tore

LionelB

It's a late 95. The non warning light instructions are for the 94.

LionelB

Upon further inspection, the location where the immobilizer warning light should be has a 964 steering wheel picture in it..... Could it be that the clock was replaced ?

Should I put a bulb in there ?

dacatz

i still haven’t got time to see what’s going on for my car yet for the my remote but in the meantime, I notice that some of the gauges lights is not working, so I decided to upgrade to led, and I remember there is actually light bulb in that slot. If u not sure what indicator is that white tab, u can remove it, use ur phone and shoot a light in that slot if it is important indicator, u can get the bulb and install one.

can anyone Help me to verify that if there is some indicator lights not working on the gauge, I will not be able to program the remote?

thanks,
Felix