991 Fault Code

[rbh]

The seasons geetings to one and all. My rev counter has decided to mimic our Christmas tree and has lit up. The nice Porsche mobile technicin (the AA) have plugged in and tel me I have a fault code recorded as P1381, however there was no insight into what this means. As anyone out there got any idea what the code could mean?

[DT398]

Google it? There are some forums talking about P1381 having something to do with valve lift but that's on a 997. Might be the same on a 991?

[rjn21]

Seems like a valve lift issue - may be as simple as an O2 sensor:

P1381
Diagnosis information Control unit DME (DFI)

Valve lift control - one bank in wrong lift

Diagnostic conditions

Short test perform
- At the end of the short test, check the following two actual values in the detail view of the short test:

1. LV01 status, bank 1 valve lift after short test
2. LV02 status, bank 2 valve lift after short test

If a fault occurred during the short test, the faulty bank will be displayed.

Oil temperature Engine < 111 °C (°F)
I Small stroke:
Engine speed 1,000 ... 2,000 1/min
Mass air flow 150 ... 400 mg/stroke
Adjustment Intake camshaft > 11°

I Large stroke:
Engine speed 2,000 ... 4,000 1/min
Mass air flow > 550 … > 325 mg/stroke (depending on: Engine speed)

Possible fault causes

Oil supply too low (e.g. Soiling (Oil circuit), Scavenging restrictor Faulty (Cylinder head ), ...)

Large differences in exhaust backpressure between banks (e.g. due to constricted or blocked passage of an exhaust branch).

Timing incorrect, a bank (Intake camshaft or Exhaust camshaft )

Solenoid valve, hydraulic camshaft adjustment Faulty (Mechanical fault or Electrical fault in circuit )

Oxygen sensor in front of catalytic converter aged / Faulty

Fault setting condition(s)

The diagnostic function detects via the lambda controllers that all valves of one bank are stuck in the small or large lift .

INFORMATION
The diagnostic function CANNOT detect which bank is faulty while the vehicle is moving.
- It is possible to read out which bank is faulty after a short test.
- The engine must still be running for this.

[rbh]

Thanks gents, Mr AA said it was ok to drive unless the display starts to flash, any opinions!

[Rockster]

rbh said:

Thanks gents, Mr AA said it was ok to drive unless the display starts to flash, any opinions!

Well, I don't know Mr. AA from Adam but my advice to you is to avoid driving the car if the engine is manifesting what could be a serious engine fault. My concern is by continuing to drive the car you could be making a relatively easy to address problem much much worse.

Thus my advice would be to get the car flat bedded to the nearest qualified shop and have the cause of the fault diagnosed and fixed.

[rbh]

Those ever helpfull people at Porsche Mid Sussex have arranged a pickup and replacement, great service!

[sidicks]

rbh said:

Those ever helpfull people at Porsche Mid Sussex have arranged a pickup and replacement, great service!

They have been faultless in my dealings with them over the last 5 years or so.

Hope you get this sorted ok!