JPP

Well.. I'm sure Marc would come over in a heartbeat if he thought he could swing it .. He had a pretty good time last trip:-). Alas, The problems I'm seeing are in assemblies and modules that came on the car from the factory, not 9m modified work. What are you doing this week, bud?

993/907

When my immob went south, took a lot of key jiggling to get it going.
Had to replace the keyway and associated steering wheel lock....doesn't sound like you have the same prob, luckily.

Gordo

JPP

Well, if I change the switch and that doesn't fix the problem, then I will probably change the keyway/steering wheel lock next because the immobilizer unit's price is astronomical.

Lorenfb

1. "So .... I do some more research .. and it seems the logical next culprits in the chain are the ignition switch and/or the immobilizer unit itself."

2. "I get the 'click' of the solenoid but starter won't engage."

I. One always needs to fully define one's problem as a no-crank or a no-start situation.
The implication from #2 is that it's a no-crank. If that's the case then;
a. bad starter/solenoid
b. weak starter signal from the ignition switch thru the starter relay, clutch switch, and/or
the alarm ECU.
c. weak battery and/or bad connections

II. If it's truly a no-start then;
a. The immobilizer ECU is not receiving the code signal from the remote.
b. There's a problem with the immobilizer ECU, but the immobilizer ECU is very reliable
and rarely if ever fails.
c. The alarm ECU may have a problem receiving the immobilizer command.
d. The DME ECM may not allow starting once it receives the immobilizer command.

Bottom line: Logical troubleshooting required and an understanding of the 993 systems!

993/907

Changed the immob ecu, helped a little.
Changed the ignition switch, no help.
Changed the keyway/steering wheel lock, cured.

Best guess is the keyway was very worn, sent junk signals to ecu and it finally cooked.

Gordo

JPP

Yes, and although I'm very good at logical troubleshooting, I'm not well versed in the system. New batteries in remotes and car, new ground strap/clean ground connections, new door actuator all working properly. However, as I've highlighted above, yes it's a no-crank problem when I use the remote to lock the car, let it sit for a few minutes and then try and start it ... , and if I let the car arm itself, it starts every time ... I think that's 'key' no pun intended. That's why the next culprit for me is the ignition switch .. it's a $70 part and that's 'absorbable risk' for me to eliminate that in the chain of possibles.

Ugh. Well, it may turn out that way for me as well, we'll see. And .. changing the ignition switch is no walk in the part I have to say .. that top screw on the switch is very inaccessible ..

993/907

Ugh. Well, it may turn out that way for me as well, we'll see. And .. changing the ignition switch is no walk in the part I have to say .. that top screw on the switch is very inaccessible ..[/QUOTE]

My body quit bending like that years ago....had the dealer do the work, since they had to order the steering wheel lock anyway.
Surprisingly, only took about 10 days from the factory.

My '95 only had about 80k at the time, but most of my trips are very short...so lots of key use.
I'm careful and much more gentle with the key now.

Gordo

96PCarrera993mg

JPP

Ok boys and girls, new ignition switch is in, keyway drylubed and cleaned front and back .... going for a drive tomorrow, wish me luck.

Lorenfb

"Changed the keyway/steering wheel lock, cured."

That's usually the problem when the immobilizer ECU key coding/programming
fails. The lock itself should not affect the no-crank problem, as that's an electrical
problem, i.e. as long as the mechanical part turns far enough to allow #50 power
(the start voltage) to get to the starter solenoid. Remember, he stated that
he hears the starter solenoid click but not cause the starter to crank.

JPP

I'm interested in looking into this as well ... any suggestions on what type of tester (simpler the better in my case .. ) I should buy that would test the system with the car running and also off just sitting. I'm assuming I would just push down the hood latch to shut off the light, then put a tester across the battery terminals and see if there's any current being drawn by anything?

Lorenfb

"then put a tester across the battery terminals and see if there's any current being drawn by anything?"

A "tester" (ampere meter) is placed in series and not across the battery.
The test current when all systems are a 'sleep' (turned off) is about
30 - 60 ma (.030 - .060 amps). The most problematic ECU from a current
drain standpoint, is the 964/993 CCU which in a few cases fails to fully
turn off causing the battery to drain in about a week.

JPP

^^ thanks Loren.
Ok, so I drove and did stop/start tests for a couple of hours: Immobilizer set by remote, drive block self set etc. ... started every time. Get the car home, pull in garage, shut if off, go to restart it ... and it fails. Fails, fails fails ....
Next up. Clutch microswitch. Anybody know the part number? I looked it up on the PET and it seems to be missing. I can only find the cruise control microswitch #18 in the picture, no clutch microswitch:


.... the one I need is the vertical mounted switch in this picture:

JPP

^^^ BTW .. I DID do the switch "by-pass" mod shown above with a tie wrap .. it closes the switch permanently so the starter isn't disabled ... and so far, the car starts ... but we all know how that goes ...

Lorenfb

"it closes the switch permanently so the starter isn't disabled"

Good. Now remember, the starter signal (#50) goes thru a relay
(R61 controlled by the immobilizer ECU and the clutch switch).
To bypass both, jumper pins 30 & 87 on R61. That way the neither
the immobilizer nor the clutch switch will affect cranking.