Abs failure, psm failure, tiptronic emergency run

Hello, I have a 2008 Porsche Cayman base model 2.7 liter automatic transmission, it has 72,448 miles on it, and I was driving home today, and a ABS failure, psm failure, tiptronic emergency run (in red) light came on. It doesn't show a loss of power, and still shifts thru all five gears in manual mode, the gear indicator blinks in 4th gear as well as the drive light blinks too, the battery was just changed 2 weeks ago, and reads 12.8 volts, still I put it on a charger for the night. The car is new to me and don't know of any service records on it other than the dealership reported they changed the oil before I bought it. I live about two hours from any porsche dealership, and this is my only car. I can take it to a local auto parts store to see if they can read for codes. Just thought someone has run into this situation before.

Certainly, read codes to see what's up. Second, check the battery - these cars are sensitive to low/old batteries. How old is yours? Has it ever been dead? If it's >5 years or ever been dead, replace it, period.

I had similar symptoms with my car - PSM and ABS failure, however my car shut down rather than entering limp mode. This turned out to be a bad battery for me. I was also adviced by a Porsche senior service tech that the battery main battery leads that run between the battery, altenator, and starter motor are prone to melt on this generation, and that he replaced this on another 987 Cayman a week prior.

An update so far, I was able to put it on an code reader and some interesting codes popped up. Electrical system failure, instrument cluster failure, left door failure, pos failure, tiptronics failure, to name most of them. The car is not in limp mode, it's an automatic and runs thru all five gears, no loss of power, the lights on the instrument panel do dim when turn signals go on though. I did find the positive terminal to the battery is loose and when I tried to tighten it, it just wouldn't get a firm seat on the battery so I will fix that as well. I don't really remember the rest. The battery tested 12.8 volts cold, when running 14.4volts, it's only a month old. I'm going to look at the fuse box tonight when I get home from work. I've also lucked out and found a mechanic that lives two doors down wants to help me out. If it doesn't turn out to be bad fuses. He's the one with the code reader.

For sure it sounds like your voltage is not fully reaching the car and its computers. I would say the most likely culprits are connections at the battery, connections at ground/alternator, and/or the power cables themselves.

Voltage tests are not at all reliable. Voltage while-running is largely irrelevant, especially since the charge system on these cars is dynamic and will change voltages based on various conditions. You need to do a load test. I do agree that if it's only 1 month old, that would probably not be the problem, but it's not unheard of to get a bad battery off-the-shelf (I've had it happen myself, not on this car). Check the cables and, more importantly, the grounds. If they are corroded or such, they can cause big problems. I've read a few threads talking about this problem... as well as the post above from @TheTheTheTheo which confirms issues like this.

it could be one of 3 things - 1. a broken clip on the wheel speed sensor (near the wheel hub) 2. dirty/malfucntioning MAF sensor 3. gearbox sensor

Those three error messages pop up on a 987 when the ABS/PSM module is having problems identifying what car it's in. BTDT after a trial session with a PIWIS -4. Why would it forget? That loose clamp on the battery terminal - can allow the system voltage to fluctuate into a range where modules start getting confused. You didn't mention what scanner was used to read it - if it was an OBD-II scanner - all it can read is emissions-related stuff. There is a lot more info in the modules that require a Porsche -capable scanner to read. Since it sounds as if you're some distance from a shop that might have a Porsche capable scanner, you might want to look in our diagnostic forum for one that you can purchase and use yourself to scan codes. When there are that many stored codes - chances are the system voltage dropped down to 10V or less - probably due to the loose clamp. I'd fix the clamp however it needs to be fixed, then charge the battery with a charger, and erase all the error codes after taking note of them. See if any come back.. bet they don't.

Update: I used a Icarsoft v3 to read codes on Cayman , and saw that I had a speed sensor not giving out a signal. It was the left rear, I put it in actual mode and put the car in gear and it didn't register any signal. I removed the tire and saw that the clip on the wiring harness had disintegrated where it connects to the speed sensor. I just purchased a new harness and am now waiting for it to come in. I will splice it in to the existing harness and all should be good, I hope. I do have a question for those who've done this or something similar before. Is it best to solder the old wires to the new wires, or use connectors (male and female) ends on the wires. I understand that the sensors are very touchy and need a good contact or it will still throw codes. Any suggestions or videos would be helpful I did see some videos on youtube using the soldering technique, and then shrink wrapping them, no connectors that I could find.

you hit the nail on the head with the broken clip on the wheel speed sensor, I will splice the new harness into the existing harness this weekend.

Glad you found the issue and it’s a relatively straightforward fix.

Thank you, I was able to splice the new harness into the old harness this weekend. Fairly straightforward as well. I did end up putting in a new abs sensor as well, only then did the codes clear. I will in the near future take a look at the remaining three wheels and see if I have a similar situation with the plug-ins at the abs sensor are rotted a away.

Just as a heads up - if one ABS sensor has failed - the other 3 aren't far behind. I proved this on my Cayenne - one failed and limited my driving a bit. I bought a replacement, had my local mechanic install it - all the codes cleared just fine, but on the way out of his driveway two of the others failed. When that happens the vehicle is undriveable - the ABS/PSM modulator thinks very odd slippage of wheels is going on, and starts pulsing the brakes whenever the vehicle tries to move. It was all I could do to nurse the car back into the shop parking lot. 3 more sensors and the problem was solved... I have a law about that... Law#8 - Parallelism: If one of two identical bulbs burns out, it's buddy is just waiting until you've replaced the one, and buttoned things up to blow out. Also applies to lots of other devices. (See sig for link to all the laws..)

Hope you are well Eye of the Tiger, I still have my 2011 987.2 and its running and purring as well as ever Cheers from Bangsar South.

don has a very valid point…. It got to the point that the harness would fail at very inconvenient moments such as on. a long drive or at night. if the condition of the remaining harnesses are not good might as well fix it. some techs may take a it ain’t broken don’t touch it approach

wave If you see me bro….keep the 2.9 purring like a tiger waiting to jump out the cage…. and check your sensor harnesses too!