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

P1374- 911 Carrera

Valve lift control checksum error - below limit

Diagnosis conditions
- Acceleration with wide-open throttle

Possible fault cause
- A valve does not switch to large lift
- Several valves (various cylinders) do not switch to large lift


Diagnosis/Troubleshooting

Perform system test for large lift

WARNING: Test is carried out while driving. Have a second person operate the Porsche System Tester 2.

1. Select system test.
2. Select "Request large 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. Carry out acceleration with wide-open throttle in 2nd gear up to 7,000 rpm. Test in manual range for Tiptronic vehicles

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.