I have a 2008 Cayenne S, 4.8, V8. 125,000 miles
The check engine light lit up today. I used my Durametric and found two error codes...
1027 : Fuel High Pressure Fluctuates
2181 : Cooling System Performance
From what I have read today, the former is perhaps the culprit for the check engine notice, whereas the latter would result in the 'Service Now' message rather than check engine.*I did have Service Now displaying already but my Porsche repair guy told me it indicates periodic maintenance is due, such as 60\90\120, and that it could only be cleared by Porsche dealer. Having looked into that more today, I'm not certain he is correct but given all these things, I am choosing to resolve the fuel code first. I suspect the HPFP might be bad so I monitored actual values with the Durametric. Noting that fuel pressure setpoint is 40bar, there are significant pressure deviations above and below; from what I observed it was ranging about 37 - 41 bar approximately. Before I buy a new HPFP and perform replacement, can any of you folks tell me what the threshold from setpoint is to trip the code? Are my observed actual value ranges normal or problematic? See screenshots.
Thanks in advance.