Paul P Posted December 16, 2022 Report Share Posted December 16, 2022 (edited) 4 hours ago, iborguk said: C152 Diagnosis information CAN PSM control module, communication NOTEInternal function test completed! Diagnostic conditions The PSM control module initially tests internal function sequences after wakeup. If they are OK, all diagnosable outputs are then tested and any faults are stored. PSM control module wakeup through: event-induced CAN message "Ignition on" Possible fault causes No power supply for PSM control modulePSM control module incorrectly codedShort circuit or open circuit in the CAN drivePSM control module faulty (in most cases the cause is not the PSM control module but incorrect coding!) Fault effects Communication via the CAN drive is no longer possible.No other control modules are able to communicate with the PSM control module. Affected contacts on the PSM control module connector Connector A: 4 ground supply terminal 31 14 CAN drive low 28 power supply terminal 15 35 CAN drive high Little bit of “narrative” on the above. Terminal 31 refers to “earth” / ground connection. Terminal 15 refers to “switched / ignition on positive connection.” the other two are (as stated) the canbus connections - the “communications line”. I don’t have the info to hand as to where that module is physically located but I would be looking to see if it’s anywhere near where you have been working and then checking the plug is properly attached and / or giving it a good drink of contact cleaner. after that. Check pin 4 has good connection to earth and pin 28 has good connection to battery positive when the ignition is on. One of your other codes mentions terminal 50. That ( I think ) is the positive connection from the ignition switch to the starter relay. so here’s another “thought” you have faults logged that might be related to the function of the ignition switch - maybe give that a drink on contact cleaner as well. edit:fuse c8 is psm control unit. Worth a check as well. Edited December 16, 2022 by Paul P 1 Quote Link to comment Share on other sites More sharing options...
Richard Hamilton Posted December 17, 2022 Report Share Posted December 17, 2022 (edited) IMHO, all the codes are due to removing the PCM, and not coding it out of the system. "C" codes are all communication faults, and although I don't know exactly why the PSM needs to be included in conversations about PCM or POSIP, it most likely does. I would find someone with a Piwis tester, and code it out. Edited December 17, 2022 by Richard Hamilton 1 Quote Link to comment Share on other sites More sharing options...
zcacogp Posted December 17, 2022 Author Report Share Posted December 17, 2022 Guys, Thanks for the answers. I think I am learning that fault codes are not logical things and there is a degree of black magic in understanding them. FWIW, the car drives perfectly fine and the only problem is the fault codes listed when I plug the code reader in. There are no warning lights on the dashboard and the ABS works fine (there is still ice on our road and I tested it yesterday). The PSM and PASM warning lights come on when it's first run after re-connecting the battery but they go out within 100 yards or so, which suggests that there is some form of self-check of the modules and they pass. PaulP, thanks. It looks like the PSM module is underneath the brake master cylinder and easy to get to. I've not done any work in that area for a while (the recent work was entirely at the rear) but I'll see if I can find 5 mins to strip the carpet out of the frunk and have a squiz at what's what. Your comments on the relevance of the different terminals is particularly helpful. RichardHamilton, good to see you - it appears that you are the go-to chap for this sort of thing! If it is just a result of disconnecting the standard-fit radio and not coding it out then I'll not fuss too much, but it would be good to find someone with a PIWIS who can confirm this. Quote Link to comment Share on other sites More sharing options...
½cwt Posted December 17, 2022 Report Share Posted December 17, 2022 10 minutes ago, zcacogp said: Guys, Thanks for the answers. I think I am learning that fault codes are not logical things and there is a degree of black magic in understanding them. FWIW, the car drives perfectly fine and the only problem is the fault codes listed when I plug the code reader in. There are no warning lights on the dashboard and the ABS works fine (there is still ice on our road and I tested it yesterday). The PSM and PASM warning lights come on when it's first run after re-connecting the battery but they go out within 100 yards or so, which suggests that there is some form of self-check of the modules and they pass. PaulP, thanks. It looks like the PSM module is underneath the brake master cylinder and easy to get to. I've not done any work in that area for a while (the recent work was entirely at the rear) but I'll see if I can find 5 mins to strip the carpet out of the frunk and have a squiz at what's what. Your comments on the relevance of the different terminals is particularly helpful. RichardHamilton, good to see you - it appears that you are the go-to chap for this sort of thing! If it is just a result of disconnecting the standard-fit radio and not coding it out then I'll not fuss too much, but it would be good to find someone with a PIWIS who can confirm this. I see you are in Cheltenham; a trip over to Lee at Cotswold Porsche should solve the coding issues. Quote Link to comment Share on other sites More sharing options...
zcacogp Posted December 19, 2022 Author Report Share Posted December 19, 2022 Guys, An update. But not much of one. I've found the time to dig out the PCM unit. It turns out that it's built into the ABS pump and lives on the RHS of the frunk area as you look from the front of the car. Here's a photo: I've disconnected the battery, and then taken the connector out of this and given both the plug and socket a good dose of contact cleaner. Having said that there was nothing visibly amiss about them; the connector was a locking thing that was very snugly home, no damage to wires, no water damage anywhere nearby .... all looked pretty much as new. I've yet to do the same with the connector on the steering column. I've re-connected the battery and it has given the usual 'PSM Inoperative' and 'PASM inoperative' warnings, as I'd expect. I'll drive it tomorrow, clear out all the fault codes and drive it again. We'll see what that brings. A trip to Lee at Cotswold Porsche is indeed an option (does he have PIWIS?) However if the problem is nothing more than some lines on screen when I plug in a code reader then I'll keep my money in my pocket (unless you think that Lee would let me use his PIWIS for 30 minutes for free .... which is unlikely - and I fully understand why). Thanks to @Paul Pand @Richard Hamilton for your input. I'll keep this updated. Quote Link to comment Share on other sites More sharing options...
sa utah Posted March 11, 2023 Report Share Posted March 11, 2023 isn't the Porsche access system alarm related ? also i believe your 8007 code is airbag related. Be good to get in scanned with Durametric at the least I would say. Quote Link to comment Share on other sites More sharing options...
rhon Posted March 11 Report Share Posted March 11 I got dtc c141 lost communication pcm (display) Can anyone help me to solve this problem.. Thank you Quote Link to comment Share on other sites More sharing options...
Paul P Posted March 11 Report Share Posted March 11 10 hours ago, rhon said: I got dtc c141 lost communication pcm (display) Can anyone help me to solve this problem.. Thank you Might be better to start a new thread but an initial guess / response. what led you to scan the car , are you looking for a particular issue ? also. Starter for 10. Have you (or previous owner) replaced the “radio/media” head unit in the car ? Quote Link to comment Share on other sites More sharing options...
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