DME 7.8 DME 7.80 · A faulty flat-base tappet can be detected because the oxygen sen-

DME 7.8 DME 7.80 A faulty flat-base tappet can be detected because the oxygen sen- sor FR for this cylinder bank enriches the mixture (FR > 1) during acceleration with wide-open throttle ⇒ see drawing below. Differ- ence from the other oxygen sensor > approx. 15 %. In the case of a fault, the flat-base tappets of the inlet valves for the entire cylinder bank must be replaced. A B A - Oxygen sensor, bank 1 B - Oxygen sensor, bank 2 1 - Select system test. 2 - Select ’Request small lift’. If "Valve lift diagnosis not ready" appears, a fault may have been stored. 1. Erase the fault memory. 3 - Activate the system test with the key F8 immediately before acceleration with wide-open throttle. The message "Drive link active" then appears. Note! If ’Request small lift’ appears, the valves remain at small lift, ie. the performance is reduced dramatically. 0-157 page 4 1555 P1351 p1351 Printed in Germany, 2000