99 C2 Code P1531 Variocam Solenoid
#136
Drifting
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Mike, if the soldering task is beyond your skill/tools - it should be possible to take the old board and new part to an electronics repair place and get them to carefully desolder and repair.. You'll need to search locally for a hole-in-the-wall type place on the wrong side of the tracks ? Maybe someone knows of a small business that would do this by mail ? The problem would be testing the board. It is easy to R&R so just reinstall and drive it? ECU Doctors would repair/replace and verify all the other functions but would be more expensive.
#137
Rennlist Member
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Mike, if the soldering task is beyond your skill/tools - it should be possible to take the old board and new part to an electronics repair place and get them to carefully desolder and repair.. You'll need to search locally for a hole-in-the-wall type place on the wrong side of the tracks ? Maybe someone knows of a small business that would do this by mail ? The problem would be testing the board. It is easy to R&R so just reinstall and drive it? ECU Doctors would repair/replace and verify all the other functions but would be more expensive.
But the car will have to sit at the mechanic shop while I drive back and forth (it's 1 hr away), as my mechanic doesn't recommend I drive the car with the ECU in the current state. So while I could probably save $500, which is a lot of money, it's about 10% of the total cost of the repairs I need to make after driving 4 hours total (using my wife's car). The mechanic also found worn chain guides (top and bottom of the actuator on bank 2), so I authorized them to repair that too. Finally, the convertible top needs a replacement, along with 2 new hydraulic rams, so the total cost for all this work will approach $6k.
My mechanic is willing to send the ECU to ECU doctors, which saves me quite a bit of trouble and time.
#138
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I'll get your the part number in the next day or so that I used to replace mine, Checking the wiring is easy. Just check for continuity at the pins that go to the vario cam solenoid. The way I check the solenoid was to run a 9V battery and see if it worked when the engine is running. That's all I did before finding the same thing in the DME as you. They went online to look for the transistor but no info was available for the 996 so I looked at other forums. I think I found the transistor info on a Mitsubishi forum. Bought one for $10 and installed it using regular solder tools and methods. It has been working flawlessly after the swap. You can do all this yourself and save a lot of money too.
Mike, if the soldering task is beyond your skill/tools - it should be possible to take the old board and new part to an electronics repair place and get them to carefully desolder and repair.. You'll need to search locally for a hole-in-the-wall type place on the wrong side of the tracks ? Maybe someone knows of a small business that would do this by mail ? The problem would be testing the board. It is easy to R&R so just reinstall and drive it? ECU Doctors would repair/replace and verify all the other functions but would be more expensive.
Where is our Mod? Can we get a sticky here?
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Mike Murphy (01-02-2020)
#139
Captain Obvious
Super User
Super User
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I kept the little bag that the new replacement transistor came in but I don't think I have the invoice anymore. But I'm pretty sure this was the kit and it came from here. https://www.diyautotune.com/product/...river-mod-kit/ I didn't use the resistor from the kit just the transistor and the mica (plastic) insulator that went under it. Essentially I just replaced what was fried in the DME.
The following where on the small pink bag the kit was in:
MK-BIP373
PCBv2.2 & PCBv3 ModKit
(1) 330o 5% Res (330QBK-ND)
(1) BIP373 (1) Mica
The following where on the small pink bag the kit was in:
MK-BIP373
PCBv2.2 & PCBv3 ModKit
(1) 330o 5% Res (330QBK-ND)
(1) BIP373 (1) Mica
#140
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So I have both P1530 and P1531 code showing recently on the 1999 C2. Sounds like a potential candidate for repair on both banks. The codes starting showing up at the same time. Wondering if that indicates anything in the diagnosis? My car has about 10,000 miles of track driving on it and it still has good power. The codes start showing up on the track after the engine is warmed up and after the track session the idle is rough. I've had to have the ECU rebuilt before due to misfires caused by deteriorated soldering. Track driving seems to create more vibration than Porsche planned for with their ECU design.
Last edited by racerxm5; 10-26-2020 at 02:12 PM.
#141
Captain Obvious
Super User
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So I have both P1530 and P1531 code showing recently on the 1999 C2. Sounds like a potential candidate for repair on both banks. The codes starting showing up at the same time. Wondering if that indicates anything in the diagnosis? My car has about 10,000 miles of track driving on it and it still has good power. The codes start showing up on the track after the engine is warmed up and after the track session the idle is rough. I've had to have the ECU rebuilt before due to misfires caused by deteriorated soldering. Track driving seems to create more vibration than Porsche planned for with their ECU design.
#143
Rennlist Member
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However, you might find the opportunity to discover “while your’re in there” work. A tensioner assembly, if failed, is like $1300, but that comes with a new solenoid. You might also have the spark plugs replaced whiles you’re in there. And you might also do a bore scoring check since the mechanic will have access to all holes from the top, and would only have to drop the sump plate from the bottom. And then inspection of the coil packs.
#144
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The last warm day we had I got mine hooked up to the durametric. Cam Timing at idle: Bank 1= 0 Bank 2 =0, at 2000 RPM Bank 1=0 Bank 2=9
The car runs fine, no misfire, no hesitation, no rough idle. Only the Code P1531.
My workshop is my driveway so if it's wet or cold, there's no work being done. I have yet to remove the engine cover until warmer/dryer weather arrives.
Wondering if the Solenoid and actuator are fine but it's a wiring issue or Cam Position Sensor Issue. I do know Cam Position Sensors can get covered in metal filings or if not seated properly or hooked up properly can send erroneous signals. A $100 CPS is a lot cheaper and easier to replace than a $500 Solenoid or $1,500 actuator assembly.
The DME is NEW from ECU Doctors. It was reprogrammed and cloned due to an Immobilizer issue over the winter.
Thoughts please.
The car runs fine, no misfire, no hesitation, no rough idle. Only the Code P1531.
My workshop is my driveway so if it's wet or cold, there's no work being done. I have yet to remove the engine cover until warmer/dryer weather arrives.
Wondering if the Solenoid and actuator are fine but it's a wiring issue or Cam Position Sensor Issue. I do know Cam Position Sensors can get covered in metal filings or if not seated properly or hooked up properly can send erroneous signals. A $100 CPS is a lot cheaper and easier to replace than a $500 Solenoid or $1,500 actuator assembly.
The DME is NEW from ECU Doctors. It was reprogrammed and cloned due to an Immobilizer issue over the winter.
Thoughts please.
#145
Rennlist Member
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^^ Pretty sure the P1531 is specifically calling that the cam position sensor is working, otherwise you’d get a different code. See post #28.
It’s probably the solenoid. Those solenoids fail way too often in my book.
However, you are correct to properly troubleshoot. Make absolutely certain the wiring is not the problem (the wiring is often NOT the problem. The wiring on this car only seems to fail when an animal chews through it.
If you have an early 5-chain motor (3.4), you probably want to plan on replacing both top and bottom tensioner pads while you’re in there.
It’s probably the solenoid. Those solenoids fail way too often in my book.
However, you are correct to properly troubleshoot. Make absolutely certain the wiring is not the problem (the wiring is often NOT the problem. The wiring on this car only seems to fail when an animal chews through it.
If you have an early 5-chain motor (3.4), you probably want to plan on replacing both top and bottom tensioner pads while you’re in there.
Last edited by Mike Murphy; 03-16-2021 at 07:04 PM.