AD07.61-P-4000-52B | Fault code description when cylinder cut-out system valves do not close with cylinder cut-out system OFF, ME-SFI | Engine 113.960 up to 5/00 with code (479) cylinder cut-out system |
1 | Fault code | Cylinder cut-out system valve on right cylinder bank (Y80) Cylinder cut-out system valve on left cylinder bank (Y81) |
2 | Fault storage Activation of malfunction indicator lamp for engine diagnosis | after the end of the test period and faults after two successive driving cycles with faults |
3 | Frequency of the test Monitoring period | continuous with cylinder cut-out system OFF approx. 5 s after the test prerequisites have been met |
4 | Fault setting conditions | Air mass too small (does not correspond to 8-cylinder engine) and additional misfires |
5 | Test prerequisites | - engine speed approx. 500 - 4500 rpm and constant - mean constant load (intake manifold absolute pressure approx. 200 - 1000 hPa) - no fault in hot film mass air flow sensor, crankshaft position sensor, pressure sensor (intake manifold) - diagnosis for exhaust gas recirculation not active |
6 | Test sequence | If the intake and exhaust valves remain closed despite cylinder cut-out system OFF, the air mass taken in by the engine is too small and it is presumed that there is a fault. Misfire at cylinders 2 and 3: cylinder cut-out system valve on right cylinder bank does not close Misfire at cylinders 5 and 8: cylinder cut-out system valve on left cylinder bank does not close |
7 | | - If faults in the cylinder cut-out system valve and misfires that can damage the TWC occur at the same time, first replace the cylinder cut-out system valve. - With fault code and both cylinder cut-out system valves do not close. - If this fault occurs, the engine diagnosis malfunction indicator lamp is activated immediately due to the simultaneously active fault identification for a misfire "damaging to TWC". |