Valve Lift Control Checksum Error - Above Limit (911 Carrera)

P1371 - 911 Carrera

Valve lift control checksum error - above limit

Diagnosis conditions
- Engine running

Possible fault cause
- Several valves (various cylinders) do not switch to small lift

NOTE: The checksum error is only stored in connection with errors in valve lift control of cylinders 1 - 6.

Diagnosis/troubleshooting

Perform system test for small lift

NOTE: The test is carried out at stand still with the engine running.

1 - Select system test.
2 - Select "Request small lift".
If "Valve lift diagnosis not ready" appears, a fault may have been stored. In this case, delete the fault memory.

The engine must be at operating temperature.
1. Increase the engine speed to 2,000 rpm and hold for 30 seconds.
2. Then press the F8 key.
3. Increase the engine speed to 3,000 rpm and hold for 30 seconds.
4. Operate the engine for 30 seconds at engine idle speed.

After 3,000 ignitions the Tester indicates whether a fault is present or not.

In order to ensure that the fault is repaired, the flat-base tappets of the inlet valves of the entire cylinder bank should be replaced if a fault occurs.