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Hi, follks; I am in a pickle and could use a lifeline.
My 2014 50k miles base Boxster PDF is not starting. I've never had this issue before, but here's how it happened and what I've tried:
1. Car sat for 2 months
2. I Tried to turn it on this weekend, and I got nothing. No lights went on, no feedback from the key insertion. It's like the battery was disconnected.
3. I Struggled trying to get the hood open, and after a million janky electrical attempts, I managed to get it open
4. I put the battery on a CTEK 5.0 for a whole day, and it appears dead. It never left stage 1 even though the battery was only 6 months old.
5. I got the battery replaced the next day. The car is now alive. All lights work, trunk and frunk open, radio works, horn, etc. However, when I fully turn the ignition, nothing happens. It doesn't crank, it doesn't turn, no feedback. Lights don't dim
6. I checked all the fuses for continuity. Multiple times. I reset some
7. I tried again. If I don't step on the break, the screen asks me to step on the break. If I don't have the car in park, the screen asks me to put it in park. So, I believe the switches work.
8. I found the relay box in the trunk and checked the 433 and 614 relays. They seem to be okay. I took them off and managed to have them closed when I applied 9V to each. Clicking was loud and satisfying.
9. I then had somebody turn the key, and with some electrical wires, I jumped the 433 Starter relay pins, and the starter kicked on, and the car was immediately on. I drove for an hour with no issues. All electronics seem to be fine
10. I got back home and plugged the 433 relay without jumper wires, but the car didn't turn on once again.
I believe the starter relay seems to be working on a bench, but when it's plugged in, there's no clicking. Checking the relay box with a multimeter, I verified that the source is getting 12 volts. The two contact pins are getting 0V when the car is off and getting weird low voltages when the key is in position 1. If I turn the key entirely, I get 2V or 8V from the relay contacts. Because of the difficulty of the position and available tools, I can't confirm what the relay contacts are receiving. It's not dead, but I'm unsure if it's getting all power.
So either the relay fails when it's plugged into the car, or it's not receiving the command to close. I heard that the ignition switch might be a problem, but I'm not sure if it's ruled since I got the car to turn on with a jumper.
First, did you make any attempts to pull errors codes with an OBDII diagnostic tool? Without knowing it there's anything else going on this will be a bit difficult to troubleshoot.
Looking at the wiring diagram, it appears that there is no simple circuit path from the ignition switch through the starter relay coil and then to chassis ground. You can create that path on the test bench and that's likely why it works there. On the car however, that coil signal path travels from the ignition switch to the Front Body Control Module to the starter relay coil then to the DME Control Unit. I would think there's something other than the relay causing the problem.
Does the key fob open the frunk and trunk? Do you have and tried the second key? A couple of Youtubes out there. One is reconnecting your key with the immobilizer. Involves putting key in ignition, turning to on and push the top button for 10 seconds. Supposedly in the manual but I did not verify.
First, did you make any attempts to pull errors codes with an OBDII diagnostic tool? Without knowing it there's anything else going on this will be a bit difficult to troubleshoot.
Looking at the wiring diagram, it appears that there is no simple circuit path from the ignition switch through the starter relay coil and then to chassis ground. You can create that path on the test bench and that's likely why it works there. On the car however, that coil signal path travels from the ignition switch to the Front Body Control Module to the starter relay coil then to the DME Control Unit. I would think there's something other than the relay causing the problem.
Thanks you for the reply. I did pull the codes multiple times, but it's been all over the place. There's no error that's always present. I should have included it in the list above. One error that I saw a couple of times and seems relevant is P3052, I believe. It has to do with terminal 30 or 50 and relay.
I will re-check them shortly and put them here.
Agreed, check the codes. Also look around for signs of rodent activity during storage.
Yes! I should have included the codes. I have the Durametric cable so I checked many times. The problem is that no error is always present. It's intermittent.
I doubt I got rodents. The car was in my garage right by the kitchen, parked by other cars. I use that garage 10 times a day. It doesn't seem like an environment friendly to critters.
Does the key fob open the frunk and trunk? Do you have and tried the second key? A couple of Youtubes out there. One is reconnecting your key with the immobilizer. Involves putting key in ignition, turning to on and push the top button for 10 seconds. Supposedly in the manual but I did not verify.
I should have mentioned that the key is operation fine. During the debug, I changed the battery and I can open and lock all doors, frunk, and trunk no problem. I also retrieved the 2nd key, which has never been used. I changed its battery and the behavior was the same. I can lock and unlock everything, just can't crank.
I've never heard about this method to sync the key. I will try that shortly!
You mentioned error code P3052, Please elaborate on that, and others, with any descriptive text that the Durametric provides. A few Google search hits mention the DC/DC converter for P3052. That item is part of the start circuit if you have the Auto Start/Stop function. Might be worth a look. Maybe some of the wiring got jarred loose during the battery change. It's located in the frunk. See below (referred to as Voltage Transformer) from the factory service manual.
You mentioned error code P3052, Please elaborate on that, and others, with any descriptive text that the Durametric provides. A few Google search hits mention the DC/DC converter for P3052. That item is part of the start circuit if you have the Auto Start/Stop function. Might be worth a look. Maybe some of the wiring got jarred loose during the battery change. It's located in the frunk. See below (referred to as Voltage Transformer) from the factory service manual.
Yah, I read somewhere this could be the problem. I didn't open up, but some people suggested just whacking up the side to re-seat stuff. I did that (After I already had the problem)
I checked the Durametric codes. I did many combinations of turning it on and off to get all potential ones. Some errors were not stable and coming and going.Engine Module Siemens EMS SDI 9
Current Fault Codes C1200:
Upper limit value exceeded
Body Control Module Front
Current Fault Codes
8782603 / 86030b:
Relay terminal 50, open circuit Warning Indicator Off
Test Completed This Monitoring Cycle Test Failed Since Last Clear
Test Completed Since Last Clear Pending DTC
Test Failed This Operation Cycle Fault Passive
12652549 / c11005:
Front-end electronics control unit, function restriction Warning Indicator On
Test Completed This Monitoring Cycle
Test Failed Since Last Clear
Test Not Completed Since Last Clear Pending DTC
Test Failed This Operation Cycle Fault Active
Door module front right (I had this one before when car was working)
Current Fault Codes
2125:
Inner door handle switch Implausible signal
Seat Electronics Driver(I had this one before when car was working)
Current Fault Codes
13:
No/incorrect coding/calibration
Relay terminal 50, open circuit Warning Indicator Off
Test Completed This Monitoring Cycle Test Failed Since Last Clear
Test Completed Since Last Clear Pending DTC
Test Failed This Operation Cycle Fault Passive
Not sure where you read the 2V and 8V in your earlier post, but with this fault code I'd start looking at that wire on Relay terminal 50 that goes to the starter relay. Here's the wiring diagram if you don't have it. I added red dots on that wire's ends.
Not sure where you read the 2V and 8V in your earlier post, but with this fault code I'd start looking at that wire on Relay terminal 50 that goes to the starter relay. Here's the wiring diagram if you don't have it. I added red dots on that wire's ends.
Thabks for the diagram. I will check for continuity.
I will have some extra hands shortly and I will get the correct voltage measurements with the terminal numbers.
the one thing I can confirm is that I do get 12V in the input pin and one of the contacts. I will get the other numbers shortly. I probably could use one of those relay testers or some little spades, as I’m just contorting myself to get these numbers.
With the vague information we have, do you think it’s worth buying a new $80 relay to rule it out? Don’t want to waste a trip to Porsche but if there’s even a possibility…
Not sure where you read the 2V and 8V in your earlier post, but with this fault code I'd start looking at that wire on Relay terminal 50 that goes to the starter relay. Here's the wiring diagram if you don't have it. I added red dots on that wire's ends.
I went to get measurements right now.
This is the 433 relay
I got these values. Note the relay was not connected when I measured this. I don't know if there's any fail-safe that prevents signals when the relay is missing
Between the contacts 85 and 86, near-zero but not zero voltage. 0.86V
Between 30 and 86, I get 9.5V
Between 30 and 85, I get 8.8V
So, the numbers seem to match. 10V in 30, and close to 0V on the contacts.
The telling part is that the numbers did not seem to change when the key was turned. Therefore, if my measurements were correct, that relay box never received any signal when the key turned.
Edit: I forgot to mention that when I used the key when the battery was flat, the key got stuck in the ignition. I had to remove the little flap on the keyhole and press a pin button to release the key. I'm not sure I damaged anything doing that.
Last edited by chickenpizzawith; 03-29-2024 at 02:18 AM.
Pin 30 is the common for the contacts. Measure from there to chassis ground. Should be equal to your battery voltage (~12VDC) You can also assume this is good since you were able to jumper from 30 to 87 to start the car.
Next find the black wire that's on Pin 86. That's the coil input, coming from Relay Term 50 at the Front BCM. Measure that to chassis ground while turning the keyswitch. I'd expect that to be 12VDC.
That's where I'd start. Do you have the Auto Start/Stop function on your car?
Last edited by thecajunboy; 03-29-2024 at 11:06 AM.
Pin 30 is the common for the contacts. Measure from there to chassis ground. Should be equal to your battery voltage (~12VDC) You can also assume this is good since you were able to jumper from 30 to 87 to start the car.
Next find the black wire that's on Pin 86. That's the coil input, coming from Relay Term 50 at the Front BCM. Measure that to chassis ground while turning the keyswitch. I'd expect that to be 12VDC.
That's where I'd start. Do you have the Auto Start/Stop function on your car?
Okay, I forgot I had some of this information stashed away on my old laptop.
This describes how the start system operates. Note that the front BCM and DME have an effect on the starter relay coil circuit, so it's possible something went wonky with coding in one of those.
Here is the official DME trouble code P3052 for Porsche 981/991 series. It may well be the relay contacts are bad, but a proper bench test should be able to identify that.
03-28-2024, 02:07 AM
Help debugging a 981 not starting
