Fault Codes Help

[Ric4s]

Hi, 

I am new to both this forum and Porsche, I have just purchased a 996 911 C4S 2003 with 62000 miles, I have just had some fault codes show up while driving slow in my local town,

ABS Failure

PSM Failure

the car cut out when coming to a junction, re started but engine rpm seemed to fluctuate slightly, I parked the car for around 15 min then re started and no code but then both came on again so parked up further 15 mins and re started (car fired but cut out twice) finally started and set off ! 

Came to another junction and car cut out ( this time car fired but wouldn’t idle which happened four or 5 times) car finally started and managed to get going but was in limp mode with further error check engine 

the initial time it happened the road surface was quiet rough and I thought possibly a wheel sensor ! I rang the dealer where purchased (250 miles away) they said sounds like alternator fault ? I have a cheap code reader and it says P1516 intake manifold switchover 1 open circuit ( is this a separate issue)

 

Could it be something simple I could solve my self ?

[DBJoe996]

Also, if you have a MAF sensor, clean it with MAF sensor cleaner.  It has been known to cause ABS/PSM faults and rough idle.

Edited October 14, 2018 by DBJoe996

[DBJoe996]

You also need to check the vacuum lines.  See this forum thread https://www.6speedonline.com/forums/996/208326-code-p1516-intake-manifold-switchover.html

[wizard]

On the assumption that your 'Check Engine' light is not flashing, checking alternator output is a straight forward task with a multimeter/crocodile clips. The positive pole  in the engine compartment will provide the most accurate readings when starting from cold/at full operating temperature/with A/C and lights on. What readings are you getting from the instrument cluster under the foregoing conditions?

 

As you will probably have to disconnect the battery at some point (reset codes), there's a process that needs to be carried out to correctly reset everything. Somewhere in the 996 forum (?) there's a detailed description of that process from a contributor called Richard Hamilton. I'll try to find that for you.

 

Edited October 14, 2018 by wizard
Remove reference to 991 forum