PSM ! light on only

I just bought my first 996, 2000 with 18K miles, love the car but I just noticed the PSM ! information light is on. No other light and this light looks dimmer than the others. Any idea what is going on or how I can resolve it. Thanks Jim

Congrats. You need to get it scanned for trouble codes by a Porsche-specfic scanner such as Duramatric.

Bummer, any idea what it might be?

It's not a common problem to have only the psm light ON without the abs warning light. I wonder if it's been like that for some time since you said the light is dimmer than the other lights. Anyhow, we really need the codes to get some clues. In the meantime, you can check if any fuses are involved. Just google porsche 996 fuse diagram.

Check fuses B9, E9 and E10.

Thanks, I'll check them in the morning. There were no lights till tonight, I have had and driven the car for about 3 weeks. Is there a recommended code reader I should buy?

The Durametric enthusiast version. Note a generic OBDII scanner can be very handy (and cheap) but it can't retrieve PSM/ABS error codes.

Ok I checked the fuses and they are fine. I am feeling a little stupid or possibly fooled. I noticed that in the daylight the light is not visible. In the garage when it is dark, the light appears faintly on. I'm currently thinking the light is not on but picking up light from the dash lights. Last night was the first time I had driven it at night. Is that possible, it never lights up bright like the others on ignition start-up? I did order the Durametric enthusiast code reader, figure I'll need it sometime in the future.

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ALL of the lights should be illuminated when you have the key in the ACC position. Per the manual, The [PSM] multifunctional light on the instrument panel lights up for a lamp check when the ignition is switched on. If there is light leaking into that lamp well AND the light doesn't come on when the key's in the ACC position, I'd be suspicious that the cluster had been tinkered with. If the car was not equipped with PSM, there might not be a light there. Does your dash have a PSM override switch in the horseshoe surrounding the center stack?

Picture of what I see in the dark garage. It looks more lit in the picture than real life.

Picture of what I see out in the daylight. No real hint of any light on.

And yes my car is equip with PSM.

Wow, that is weird. Almost seems like something funky with the cluster - I don't think that's light bleeding over. Does the light change when you toggle PSM off? I'm trying to remember....I think mine does...

Rick, when you drive at night do you see that light at all or is it invisible or at least as detectable as the other warning lights.

My guess: someone removed the psm warning light bulb and the dash light bleeds into the empty hole. Go to the dark garage and turn off the low beam so the instrument cluster will go dark. Then you should not see that dim psm warning light.

I bet ya this is what you'll find if you look behind the gauge cluster.

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100% dark for me. If I thought any of my lights might be coming on I would be posting on this forum

I have to hand it to you guys the missing bulb makes sense. I tried earlier to turn off the instrument cluster as you suggested in the dark garage but was not successful. One question/observation is when I turn the ignition all the warning lights light up but not the PSM ! light. Its it supposed to? That supports the missing bulb theory.

Yes, ALL of the lights should illuminate. The ACC position is a test mode for you to verify that all of the warning lights are functional. Since this one isn't, it's either dead or (as several of us have now theorized) missing. Does your ABS system work - i.e. if you apply the brakes HARD as in a panic stop, do you feel the pulsing of ABS? PSM uses the ABS pump; I'm curious if your ABS is still functional. One of the "hack" methods to disable PSM involves disconnecting a wire at the brake fluid reservoir in the front trunk. I'm guessing that maybe someone did the following to your car, and then removed the PSM light to eliminate the distraction of the repeating PSM failure alert. "2. Unplug “the clip going to the yellow sensor on the side of the brake fluid reservoir. … Disconnecting the sensor … did disable PSM and ABS still worked. I was able to back the car into corners at will and engage ABS. You do get 2 warning lights at start up and every ~15min for PSM failure and brake fluid sensor. It's annoying but not that bad.” Downside: No warning if you lose too much brake fluid. But assuming this can be connected to a rocker switch and one only uses it for track or drifting sessions, then one can check the fluid again at regular intervals."

Here is what I see when I turn the key to the on position in the garage. The PSM ! and the light to the right of it doesn't come on.

Interesting, the PSM override light is there but the PSM warning light is missing. It sure seems like someone ripped the light out. Did the person you bought the car from track it often?

BTW, that triangle "!" light should come on during bulb check and blink when PSM kicks in. It does NOT mean your PSM has issues. It's moot anyways as it sure seems like you're missing that bulb. Only one way to find out...should be easy to remove the cluster and put a new bulb in and see what you find. My suspicion is the PSM kicked in intermittently for some unknown reasons during normal driving and someone tried to diagnose it to no avail so they just got rid of the bulb.

My understanding is the car was never tracked but that was from the second owner that bought it from a dealer 2 years ago. I don't really see any signs that it was driven hard. What bulb goes in there, do I have to get it from a dealer? I may try to put it in this weekend. Also should get the Durametric code reader soon to check and faults. Thanks to all for the help so far.

I kid you not... it's the Rennroach's fault! :-)

Damn Rennroach

So I go to the Porsche dealer parts department and they have never sold a bulb for the instrument cluster, say they have just replaced the while cluster. Then it took a while to figure out the part number for the bulb and of course they didn't have it. The part number is 999-631-302-90 (12V 1.2 watts). I went home and ordered it online. When it comes in I'll post what happens once it is installed.

Well I received my Durametric Cable and checked for faults and didn't find any but I did get a red circle with a ! in it? Anyone know what that means? I have yet to receive the bulb for the PSM indicator light (triagle with the ! in it). Also can you help with the RPM rev limit information. Number Ignitions Range1 1100/486h Number Ignitions Range2 0/0h Does this mean it was taken to red line 1100 time but not over? Thanks Jim

No, it means you had 1100 range 1 ignitions (somebody bounced it off the rev limiter a few times, and it last happened when the engine had accumulated 486 operating hours. If you dig around some more in the Durametric software, you will find the total number of operating hours for your engine. If the total is, say, 900 hours, you know that the last range 1 ignition took place 414 operating hours ago. If the total is 490, you know that somebody redlined it quite recently. For OUR cars, range 1 ignitions are OK and range 2 ignitions are bad; these numbers are not concerning. The ranges are different for newer Porsches; we just have the simple (and fairly understandable) 2-stage system. You should be able to look at the detailed results and get the fault code(s) listed for the PSM system. That's just the overview page showing what stuff was fine and what needs more attention. The yellow ! means an information-only fault, the red ! means an actionable fault (i.e. there's something that needs to be fixed). Click the + next to PSM in the list of available modules on the left side of the screen. That will expand the menu so you can see all of the PSM options. Click the line that says "Fault Codes" to see the code(s) stored for your PSM module.

Thanks for the explanation, looks like the rev limiter happened 36 hrs ago before I bought the car. It happened at 464 hrs and there are 500 hrs on the car (my previous number of 486 was wrong). So what RPM would that be? And if there is a rev limiter on the car how do you get to range 2 and what is that rpm value? As for the ABS/PSM 5.3 fault. I opened this by way of the individual module and got this below Unable to connect to module. Would missing the bulb cause this? Is the ABS/PSM not working and that is why they took out the light. Hmmmm.... What should I do now? I'm not too upset with previous owner, got the car for a good price and not sure he knew anything about it, he bought it from a dealer. Thanks in advance for all the help on this.

It sure seems coincidental that the PSM module is not responding and the PSM bulb appears to be missing. I'm guessing that a PO used one of the known tricks to defeat PSM - or maybe swapped out the PSM hardware for an ABS-only system - but I readily admit I have no idea if it's actually possible to do the latter. All this is based on stuff I read in other PSM threads in various places around the interweb. This is one of the most complete threads - at least as far as theoretical modifications to PSM - I've found: http://www.renn-list.com/Best-way-to..._10489303.html

The plot thickens!! Assume the ABS works? How would you proceed? Where is the PSM/abs module and can I get a part number off it to see if it is the right one?

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A pic in post #2 in this link http://www.6speedonline.com/forums/996-turbo-gt2/230674-abs-psm-fault-code-4460-a.html It's a TT but yours should be similar. I would start with checking the electrical plugs there and recheck all abs/psm fuses with a multimeter (in addition to visual).

I'd also go find an empty parking lot, accelerate to 25MPH, and stand on the brakes - just to make sure your ABS is firing. Worth verifying, since ABS and PSM use the same pump on your car.

Did the parking lot test, ABS is working. Unfortunately now my suspension is creaking both front and back. Any ideas what that is? Guess the hard braking woke up the 16 yr suspension. It is very annoying.

New control arm bushings should fix many suspension groans. Congrats on the ABS test - at least you now know that a fundamental safety feature is working correctly.

I think I have isolated it to the front inner control arm bushings or sway bar bushings, seems to be a little better after jacking up the car. New Problem, not my day with this car. The key appeared to be getting stiff, I put a little lubricant on my key, couple hours later the ignition is not working well. Doesn't seem to want to lock the steering wheel when key is out and I can't lock the car. AC wouldn't work unless I turn the key back after starting. Just read I may have the dreaded failed ignition. Good thing I love this car and the challenge of repairing it myself. Any advice on the ignition? Beer time!!!

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Your car needs a new ignition switch. The $30 part, not the $300 part. We ALL have to do that one eventually. And repeatedly, if you own the car long enough. There are about 3.7 billion threads here including one current one on this topic, so I'll leave you to your own devices for researching this one.

Back to the PSM light problem. When I receive the bulb in the mail, should I go through the process of installing it and see what happens or just leave it alone? I have ABS, don't know about PSM. Would the lack of a bulb prevent the Durametric from seeing the PSM module, I assume not? Oh does it make sense that the bushing squeak is now much better after I drove it harder. Did stopping hard to test the ABS position the bushing in a squeaky place and as they warmed up and they reseated? Strange.

I've been through a world of PSM woes and in the end just gave up on it as its my track car. Without it my laps have improved. There is also a pre-charge pump (shared by the ABS system which still functions perfectly) on the passenger side of the frunk that may have issues. This is where the Durametric pointed me the issue was. I sent it off for testing, it proved faulty, and had it professionally rebuilt. After installation the PMS system still didn't work at all. After spending about $2K chasing this issue I'm done with it.

Yeah I'm hoping not to go down the $2K road. Is there any way to tell if the PSM system is working, is there a driving test like the ABS?

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Go to an empty wet (or dry) parking lot and see if you can slide the rear around under power. You'll know.

Got it, works like the traction control on my 330ci BMW. I occasionally turn it off to fish tail the car around corners to have fun when roads are wet. One issue though, don't usually drive the 911 in wet weather.

Took some pictures of the brake fluid reservoir area checking to see if any of the PSM hacks 5CHN3LL mentioned above had been done. The wire to the sensor on the fluid reservoir is connected and I don't see any other wires out of place or cut. One thought expressed was the ABS/PSM module was replace with just an ABS module and they took PSM ! indicator light out to keep it from coming on. Can anyone tell from the pictures if that is the case? I really don't want to tear apart the instrument panel to put in the missing bulb if it is going to come on cause the PSM module is missing. Plan at the moment is to test if the PSM module works the next time the roads are slick, if it is I'll put in the missing light. Thanks for the help 5CHN3LL, sorry about the wheels.

Got caught in the rain tonight with the car, opportunity to test if the PSM works. To my surprise it did. I kept trying to fishtail and the PSM wouldn't let me after an initial lose of traction. Turned to PSM off and fishtail away. Now I plan to put the missing bulb in place. WTF

Ok, I give up. Took the cluster apart only to find the bulb is not missing. Theory shot. Replaced the bulb anyway thinking it was burned out. Still have the same issue faint light bleed through, not surprising and the light doesn't come on when the key is turned to position one. Bottom line is the PSM system appears to work, I just have to put up with a faint PSM ! at night. Unless someone has any other ideas.

That is very strange. What happens if you turn on the parking light (the background light in cluster should light up) and then turn the key to position I?

Tuned on the parking lights, key to #1 position and same, all the indicator lights over to the PSM off are lit. The PSM triangle ! is very faint in a dark garage. Something is not right, and the fact that the Durametric software doesn't acknowledge the PSM exist is puzzling. ABS and PSM appear to work so I guess Ill just drive on until something changes and I need to address it.

Wonder if this could be just overly bright adjustment of the Instrument Illumination have you tried to manually adjust the instrument and switch symbol brightness. When it is light up bright it means, PSM control unit is working. It shouldn't be light up even dimly unless there is some sort of wiring problem. I'd pull and check every fuse. I assume there are no errors from Durametric, can you see the VIN of the ABS pump, does it have the same VIN number as the car. Not sure if durametic can do everything you may need use a PIWIS tool. If the light has illuminated under normal circumstances you need to diagnose it. I'd bring it to dealer if you can't get access to the PIWIS tool. Also possible Brake light switch MAF ABS unit

Is that light supposed to light up when the key is in the 1 position, mine doesn't?

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all lights are suppose to light up for a sec, and then go off, this is to test that the lamps are working. you may have an issue with the instrument cluster.

It didn't cross my mine till now. Durametric can test the instrument cluster bulbs! In a dark garage, in Durametric under "Instrument cluster" select activation and test then watch the light show. If the psm light lighs up, at least it's more likely the cluster itself is ok. I know it doesn't solve your problem but you may as well get more info.

I checked the wiring diagram. The PSM control unit has 3 wires connected to the instrument cluster directly and one wire connected to the second K-line on the OBDII diagnostic port, again directly. Since your Durametric can read the airbag, which is on the same K-line as the PSM, your second K-line is fine. So that leaves wiring and PSM control unit as the culprit for the "no communication" problem with Durametric. There's not really a whole lot you can try other than checking the ABS/PSM side connector where it plugs into the pump unit itself in your photos. There are no other connectors/splicing between it, the cluster, and the diagnostic port. With the battery disconnected, unplug the big black ABS/PSM on the ABS pump unit and check if the pins look find, then reconnect everything. I suspect either your instrument cluster is bad or part of your PSM unit is bad. Either case, you can send the unit to modulemaster.com for repair for a couple hundred dollars.

Ahsai, I tried to test the indicator lights with my Durametric but was unable. I have a 2000 C2 with a K01-K03 instrument cluster, selecting activation gives you a number of things to test but not one that tests all indicator light. I noticed the next generation instrument cluster (2002 -) has that option. Thanks, was a good idea.

Bummer, would have been nice...the wiring info I mentioned should be accurate though as I checked the MY2000 wiring diagram.

Thanks for the help

Still haven't resolved this issue yet but a new thing I realized is to the left of the PSM "triangle" ! light I have a T/C off indicator light. Assume this is Traction Control. Do others have this light, it never lights up and there is no reference to it in the manual? I thought maybe I have Traction Control instead of PSM but my Option sticker says 476 "PSM"

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TC = PSM

Why do they have a T/C off and PSM off light?

Something i would try, before chasing the psm ghost anymore is to change the ignition switch. This has cured many 996 electronic gremlins. As you say in a previous post it is maybe on its way out and is common on the 996 especially with heavy key rings.

Good idea, changed the switch about a month ago, no change.

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As I understand PSM/TC on my 2004, there are two lights - the first is the "triangle" also called an "information light" Information light - The PSM information light in the instrument panel lights up for a lamp check when the ignition is switched on. - The light indicates PSM intervention even when PSM is switched off (brake regulation in the event of one-sided wheel spin). The second light is the "warning light" Warning light - The warning light in the instrument panel lights up in combination with the indicator light in the rocker switch for a lamp check when the ignition is switched on. - In combination with the indicator light in the rocker switch, the light indicates that PSM is switched off. - The lights in the instrument panel and in the on-board computer indicate a defect. PSM is out of order. The fault should be remedied immediately at an authorized Porsche dealer. This info is from the 2003 Owner's Manual - I'd be curious to know what your 2000 Owner's Manual says.

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If you miss a gear on a downshift, meant to be in 4th but actually are in second, and you let the clutch out abruptly you can get into range 2. I don't know the rpm value but it is higher than you ever want.

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Also, looks like 2000 was a transition year for Porsche regarding the offering of PSM as an option (which you have). Prior to 2000 there was just a basic traction control system with no PSM option - maybe the dash hadn't been updated to reflect this on your car.

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That sounds like a reasonable explanation, the T/C off indicator light seems inactive. When I switch The PSM toggle switch the PSM off light lights up. T/C doesn't ever come on and is hard to see even exists in the control panel.