Intermittent PSM Fault
06-07-2022, 11:15 AM
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Cruisin'
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Intermittent PSM Fault
Hey 
My 997.1 C2 2005 (UK version) seems to have an intermittent PSM warning light that comes on the dash. The fault code that I read on PSM module is "C150 - Communication DME control unit (drive)".
Local Porsche Specialists told me that this fault is very vague as it basically could be anything on the PSM loop
It can appear as 'PSM fault' on the dash alone or together with 'ABS fault', but 95% of the time it's just the 'PSM fault'.
Usually happens every other time, so 50% chance pretty much if it'll come on.
The warning light usually comes on when the car has been started and will remain until engine off, I've never seen it clear while still driving.
Next time the engine is started it may be gone and when it's gone, it's usually gone for the entire journey. However, I did see occasions where it appears while driving too, although rare. Twice I believe it was triggered when going over a biggish pothole.
Warning might not appear for multiple journeys in a row, but then start appearing again multiple times in a row, usually at the startup.
It's possible to start the car and see the warning, shut it off, restart, and not see the PSM fault again, although I only done it once or twice for testing purposes.
Things already looked at
Thank you
My 997.1 C2 2005 (UK version) seems to have an intermittent PSM warning light that comes on the dash. The fault code that I read on PSM module is "C150 - Communication DME control unit (drive)".
Local Porsche Specialists told me that this fault is very vague as it basically could be anything on the PSM loop
It can appear as 'PSM fault' on the dash alone or together with 'ABS fault', but 95% of the time it's just the 'PSM fault'.
Usually happens every other time, so 50% chance pretty much if it'll come on.
The warning light usually comes on when the car has been started and will remain until engine off, I've never seen it clear while still driving.
Next time the engine is started it may be gone and when it's gone, it's usually gone for the entire journey. However, I did see occasions where it appears while driving too, although rare. Twice I believe it was triggered when going over a biggish pothole.
Warning might not appear for multiple journeys in a row, but then start appearing again multiple times in a row, usually at the startup.
It's possible to start the car and see the warning, shut it off, restart, and not see the PSM fault again, although I only done it once or twice for testing purposes.
Things already looked at
- I've replaced the battery to the uprated one myself as for this problem I read that it could be due to weak battery. This changed nothing
- Indy replaced the clutch switch. That did nothing
- Indy replaced the break light switch. That did nothing
- Indy said that PSM module was coded wrong, so they recoded it. That did nothing
- Indy said that they manually went through every single module to see if there could be any wrong coding or other fault that could've caused a chain reaction into PSM. That did nothing
- One Indy Mechanic had told us that we might need to change the abs pump as it could be faulty chip on there, but the other mechanic dismissed it so this was not looked into further
- I've asked Indy if maybe water ingress could be the cause and they dismissed it as unlikely, not been looked into further
Thank you
Last edited by pipi; 06-07-2022 at 11:33 AM.
06-07-2022, 11:24 AM
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Cruisin'
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I started this as a separate thread as the original one with this and another issue was too long, but in case you might want to refer to it:
original -> https://rennlist.com/forums/997-foru...ition-off.html
other issue with flashing hazards, unsure if related -> https://rennlist.com/forums/997-foru...ition-off.html
original -> https://rennlist.com/forums/997-foru...ition-off.html
other issue with flashing hazards, unsure if related -> https://rennlist.com/forums/997-foru...ition-off.html
