Turn the key no response !! 2000 Boxster base
 

I replaced the battery, I replaced the electrical portion of the ignition switch. As to the key, the cylinder it is not acting up, or difficult to turn etc. No electronic flashes or other difficulties.
So, why is turning the key so unreliable? Nothing happens, all I see is dash lights, no noise no response.
Thought I had it fixed by closing the windows, top up, and locking the doors with the key in the door lock. It worked!! ... then it didn't!
I have learned not to do anything unless you disconnect the negative side of the battery to avoid a check engine light turning on.
I do not have a working electronic key transmitter so I only use the regular key that I have.

So back to why won't it start??
Can the central locking immobilizer be so inconsistent as to work on any given try and then not the next? I know the immobilizer has a fuse, could this still be the problem?
As electronics is not my strong suit how careful must I be with the immobilizer unit?
Is there another area I need to check?

There are many posts on the forum about this issue, am I missing something?

Thank you for any advice!
Frank

Go back and check the connections on the ignition switch.

If it wasn't the connections on the ignition switch, come back and tell us what was happening to the car that caused you to start working on it in the first place.

Turn the key no response !! 2000 Boxster base
 

Mike,
Not starting was the original problem...
Putting in a new ignition switch was my first action to remedy the no start problem.
I thought the new battery would be helpful too as it was old.
125,000 miles on the car, but it is in great shape!
Thank you

Turn the key no response !! 2000 Boxster base
 

JFP,
Go back and check connections?
It is a plug in switch, should I remove it and reconnect?
Thanks

A couple of thoughts:

1) If it's a manual, is it possible the clutch switch is going out. There's a switch that senses when the clutch is pressed in. If it goes bad, it won't turn over.

2) Did you get the new key switch fully seated? If it's not all the way into the key socket, then the starter won't function. Electrics will turn on, all seems well, but won't start. I had that issue when I replaced my key switch. The new switch was not fully seated and it wouldn't do a thing. Loosened that allen screws, pushed hard to fully seat it and then it worked just fine. Yea, you did have the same issue before you replaced the switch, so not likely it. But who knows.

Good points from RotMilky

Also, in your first post you mention that you dont use an electronic key with the transmitter ? What kind of key do you use ? Is there a transponder chip in this key ? I have seen some setup where a normal key from home depot(no transponder) is used and the transponder permanently glued near the ignition switch behind the dashboard. This can cause this kind of behavior that you see there.

Just a tought.

Turn the key no response !! 2000 Boxster base
 

Pomerlo,
The key is just a plain key with a Porsche logo on it
All it has is a mini light built into it
I will check your idea out.
Thanks
Frank

Turn the key no response !! 2000 Boxster base
 

Rotmilky,
I have ordered a new clutch switch from Pelican, as it is a 5 speed manual.
This would seem to be a good item to address as I do not know the cars history.
I will also re-seat the electronic key switch as I have already been advised.
When the part comes in and I get it installed I will post the results.
Thank you very much
Great info.
Frank

Just a bit more info.....
The car runs fine, I put in a new air-oil separator, had oil and filter changed, also had the break and clutch fluid changed. People who do not know better think it's new.
A pleasure to drive!!!!

You can bypass the clutch switch by unplugging it and inserting a jumper wire between the wires.

Turn the key no response !! 2000 Boxster base
 

Update.....
I have installed the clutch switch, it works fine.
The car now responds to my turning the key for a start about 80% of the time.
The trick to starting now resides with locking and unlocking the car.
It is most reliable when it has just been unlocked, and not so on a restart.
It appears to be all about the immobilizer.

Thanks for all the advice
Frank

Board level repair-M535-Fixes W-Lead issue
 

If you are talented with soldering (or just decent at it) and electrical troubleshooting; please attempt the following "Irogag's Sure-fire Immob Recondition":

Alarm control unit: M535
Year: Mine is 2000 Boxster Non-S, Not sure how many others this applies to. A few for sure.
Model: 986 (possibly others)


Before Beginning) IF you have a system tester or diagnostic tool, it could be very useful to know what Code is displaying. For example, "Code 21 W Lead" will mean you should focus your skills near the Plug I, control module, Terminal # 23. If W Lead ''goes true" every time, and that it passed to the alarm control unit. This was the issue I found. It's very simple: if the signal is NOT there, then it's a problem outside the module elsewhere in the vehicle. If it's there, and it seems like the signal is present up to the module, then start to suspect the M535. The R1 relay in the photo attached was bad, and I just bought it for $0.75 and problem solved.

But without a diagnostic tool, I can take you through about 80% of alarm issues (with the control module) solved by this step-through:

1) E-1 Fuse OK?
2) F-5 Fuse OK?
3) Does the door lock button (central locking button) operate? Does system recognize both doors? Do both doors lock? Does rear lid get recognized? Does front interior lights come on when front compartment lid is open? The procedures assumes yes to all these. If none of this works, start there. The lids may not matter, but again it's best to get all these inputs correct to get a good 'lock' for alarm readiness.
3)Disconnect neg (-) Battery cable.
4)Remove seat
5)Unplug Plug I (blue) and Plug II (black) from the M535. Pull on each wire in the plug harness to verify they are tight. Check for anything obviously bent, burnt, broken or loose on all plug holes on plugs and all pins on module.
6) Remove M535 and remove plastic around it. Take the PCB to a workbench.
7)Use a clean toothbrush and denatured alcohol to clean top and bottom of PCB. Clean it really well.
8)Unsolder and replace the blue capacitor in the center.
8.1) Test fuse next to plug II (black PCB-mounted plug connector). Fuse OK?
9) Apply the necessary voltage to the necessary 2 pins on each relay, R1 to R7. Take your time and look up each part # on the web to know what voltage to apply. I used just a regular voltage power supply which let me vary the voltage as required.
10) As you apply voltage, check the contacts with an ohmmeter. A open should always be O.L. or >1 Meg-Ohm. A close should always be < 0.5 Ohms. Any readings besides these mean the relay is suspect. I applied it with a direct voltage right on solder side of the board. Alternately, you can use a magnetic to move the contacts but be warned this may not detect all issues using a magnet alone. It's best to test with actual voltage similar to what the car is putting out.
11) For 'double pole' relays check both poles and both contacts on each pole. Check the N.O. is open with no power. Check the N.O. closes with power. Check the N.C. is closed with no power. Check the N.C. is open with power. It sounds obvious, I know, but you really must carefully check each pin on those relays to prove they work. My issue was with a N.O. contact staying open, no matter what I did to the relay on R1.
12)If you've made it this far and found absolutely no issues, or even if you've fixed something, it's best to reinstall the module now to test it in the car. Reconnect (-) battery cable. Notice any changes ?
13) If no changes are noticed, please make sure you did step 8, and Step 9 thru 11 carefully. Double check all your work. I say this because we may destroy your M535 in the next steps so be advised. If you've made it this far your issue is likely not the module. I would send it in for repair, buy a new transponder, key, and M535 from the website guys, or start troubleshooting elsewhere in the car first. If you are still stuck and convinced it's the M535, and you have proof to back that up, please continue below:
14) We are going to 'reflow' all the solder on the board. I highly recommend looking up ''reflow a PCB in oven" on Google for how to do this. Alternately, what I did what cover the relays and capacitor with about 3 sheets of heavy duty aluminum foil. Then, I applied heat from a heat gun directly at the ICs and pcb components of the module.
15)When reflowing, always place a small 'mouse poop'sized stick of solder on the largest IC. This will turn into a ball when you know you are hot enough to melt all solder on board. Finally, it's crucial to keep the PCB level to keep from flowing solder away from IC pads.
16) Resolder or just put a lot of heat at the pins of the PCB-mounted plug connectors. Skip this step if you reflow in oven, as that pretty much covers all the solder on the whole PCB.
17) Wait patiently for at least 20 minutes to even move the board.
18) Reinstall module to test in the car.
19) Again, I am assuming you've already tried all the other clutch safety switch, ignition lock, and other various component troubleshooting. The M535 is pretty simple, so if it's not getting an obvious signal like K-Lead or W-Lead for real (which was not my case, it was getting those just not interpreting them via the module correctly) - then start your troubleshooting on much more simple terms such as checking resistances, checking that grounds are grounded, etc.
20) If you did not fix it by now I would pay the $600 or so for the full repair. But I would advise first to prove the issue is immobilizer based and not a much more simple issue with the key, the ignition switch, etc.

NOTE) None of these steps above address non-control modules, such as issues with your ignition lock, your transponder, your motion sensor/IR sensor, or any other parts of the car.

Positive ground
 

My problem turned out to be a weak "positive" ground in the engine compartment. It was rusty, and if I wiggled the cable and turned the key the engine would start. Disconnect the battery. It is located in a black plastic box next to the power steering reservoir. Use a screw driver to pop the box open and a 14 mm socket to remove and clean the nut.
http://986forum.com/forums/uploads02...1578282973.jpg
http://986forum.com/forums/uploads02...1578283025.jpg

Can you elaborate on how to test the relays? Do I test them from the underside?

Eg. One of my relays are: V23072-C1061-A108 ++ 24311

Did you try cleaning the "positive" ground? I chased a non-responsive key issue for quite a while and it was just a rusty connector. Make sure you disconnect the battery because this is directly connected to the positive terminal of the battery.

Yes just turn PCB over and you will find the pins below the relay. For example (check my work here, as I didn't see A108) but on the 5pin relay in this dataheet :
Mini Relay K (Open – Sealed) Automotive Relays PCB Relays https://www.electrokit.com/uploads/productfile/41019/V23072.pdf

You would set power supply output to 12V and apply positive to 1 and negative to 2 ( if it's not marked as - and +, polarity is indifferent). Test ohms across 4 to 7 for N. O. AND 4 to 5 for the other N. O. I am basing all this off the 1 Form U/X, 2 No diagram. So if yours if different adjust accordingly

Thank you. Do you know how I can purchase new relays? What numbers should I look for?
Do you have any sites that you use?

Irogag, thanks for your very informative posts on board level repairs of the M535. I have started having some weird issues with my M535 where doors do not lock etc. I have changed both locks but that did not help. When I check input states, it incorrectly shows both doors as being closed and locked, frunk and engine compartment also as being closed when neither of these is the case. So the alarm module tries to lock but sees that they are already locked and does nothing other than make a brief buzzing sound. I can lock the driver door using the key and can unlock that using the fob. Both open and close positions of the key in the driver door show fine when monitored using PIWIS. There is no water damage. Where would you advise I should look? I do not think there is a problem with the relays as the problem has to do with the alarm module not seeing the correct state of many of the inputs. The capacitor visually looks fine and when I check it while in circuit using an ESR meter, shows as 200uF. Would appreciate any of your insight into this